1032-00003 · Client 1032 · Transaction Documents/Underwriting

draft-lockup-selling-shareholder.docx DOCUMENT Capital Markets

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CONFIDENTIAL — DRAFT FOR DISCUSSION PURPOSES ONLY

FORM OF SELLING SHAREHOLDER LOCK-UP LETTER

(To be printed on the letterhead of the applicable selling shareholder — Rheintal Industrieholding GmbH or Kestrel Capital Partners AG)

[●], 2026

Westbridge Securities LLC as Representative of the several Underwriters 383 Madison Avenue New York, NY 10179

Attention: Jonathan Hartwell, Managing Director, Global Equity Capital Markets

Re: Proposed Initial Public Offering of American Depositary Shares of Halcyon Semiconductor Aktiengesellschaft

Ladies and Gentlemen:

The undersigned understands that Westbridge Securities LLC ("Westbridge" or the "Representative") proposes to enter into an underwriting agreement (the "Underwriting Agreement") with Halcyon Semiconductor Aktiengesellschaft, a German stock corporation (Aktiengesellschaft) organized and existing under the laws of the Federal Republic of Germany, with its registered office in Munich, Bavaria, Federal Republic of Germany, registered with the Commercial Register (Handelsregister) of the Local Court (Amtsgericht) of Munich under registration number HRB 217458 (the "Company"), the selling shareholders named therein, and the several underwriters named in Schedule I thereto (collectively, the "Underwriters"), for whom Westbridge is acting as representative, providing for the public offering (the "Offering") of American Depositary Shares ("ADSs") of the Company, each ADS representing two (2) ordinary shares (Stammaktien), no par value (Stückaktien), of the Company (the "Ordinary Shares"). The ADSs are to be issued pursuant to a deposit agreement (the "Deposit Agreement") among the Company, Meridian Trust Company, N.A., as depositary (the "Depositary"), and the holders and beneficial owners of ADSs from time to time. The Company intends to file a Registration Statement on Form F-1 (the "Registration Statement") with the United States Securities and Exchange Commission (the "SEC") under the Securities Act of 1933, as amended (the "Securities Act"), in connection with the Offering, and to apply to list the ADSs on the Nasdaq Global Select Market under the ticker symbol "HCYN."

The undersigned further understands that the Company and the selling shareholders intend to sell in the Offering a number of ADSs to be agreed upon with the Underwriters, consisting of both newly issued Ordinary Shares (in the form of ADSs) by the Company and existing Ordinary Shares (in the form of ADSs) by the selling shareholders, all on the terms and subject to the conditions set forth in the Underwriting Agreement.

The undersigned is a selling shareholder who will sell [●] Ordinary Shares, equivalent to [●] ADSs, in the Offering pursuant to the Underwriting Agreement. Specifically:

[For Rheintal Industrieholding GmbH: The undersigned will sell 8,500,000 Ordinary Shares (equivalent to 4,250,000 ADSs) in the Offering.]

[For Kestrel Capital Partners AG: The undersigned will sell 4,300,000 Ordinary Shares (equivalent to 2,150,000 ADSs) in the Offering.]

The undersigned acknowledges that the Underwriters are entering into the Underwriting Agreement, and proceeding with the Offering, in reliance upon this lock-up letter (this "Lock-Up Letter") as a material inducement, and that the agreements and obligations of the undersigned set forth herein are an essential condition to the willingness of the Underwriters to proceed with the Offering. In consideration of the foregoing, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees as follows:

Section 1. Definitions

As used in this Lock-Up Letter, the following terms shall have the meanings set forth below:

"Lock-Up Period" means the period beginning on the date of the final prospectus relating to the Offering, as filed with the SEC pursuant to Rule 424(b) under the Securities Act (such date, the "Pricing Date," which is currently targeted for on or about July 1, 2026), and continuing through and including the date that is one hundred and eighty (180) calendar days after the Pricing Date (currently targeted for on or about December 28, 2026). For the avoidance of doubt, the Lock-Up Period shall commence on the Pricing Date regardless of whether the Pricing Date is later than the date of this Lock-Up Letter.

"Lock-Up Securities" means (i) all Ordinary Shares of the Company beneficially owned (as determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and the rules and regulations promulgated thereunder) by the undersigned as of the date hereof or acquired by the undersigned during the Lock-Up Period, (ii) all ADSs beneficially owned by the undersigned as of the date hereof or acquired by the undersigned during the Lock-Up Period, and (iii) any securities convertible into or exercisable or exchangeable for Ordinary Shares or ADSs beneficially owned by the undersigned as of the date hereof or acquired by the undersigned during the Lock-Up Period, in each case including, without limitation:

(a) Ordinary Shares directly held of record by the undersigned;

(b) ADSs directly held of record by the undersigned;

(c) Ordinary Shares or ADSs held by or through any trust, partnership, limited liability company (Gesellschaft mit beschränkter Haftung or Kommanditgesellschaft), or other entity directly or indirectly controlled by the undersigned;

(d) any options, warrants, rights, or other securities convertible into or exercisable or exchangeable for Ordinary Shares or ADSs, whether or not vested or currently exercisable; and

(e) any Ordinary Shares or ADSs acquired by the undersigned during the Lock-Up Period, whether through open market purchases, private transactions, the exercise of options or warrants, the conversion or exchange of convertible securities, or otherwise.

Notwithstanding the foregoing, Lock-Up Securities shall not include any Ordinary Shares (or ADSs representing such Ordinary Shares) being sold by the undersigned in the Offering pursuant to the Underwriting Agreement (i.e., 8,500,000 Ordinary Shares in the case of Rheintal Industrieholding GmbH, or 4,300,000 Ordinary Shares in the case of Kestrel Capital Partners AG, as applicable).

"Retained Shares" means all Ordinary Shares and ADSs beneficially owned by the undersigned after giving effect to the sale of Ordinary Shares (in the form of ADSs) in the Offering.

[For Rheintal Industrieholding GmbH: As of the date hereof, the undersigned beneficially owns 47,945,000 Ordinary Shares. After giving effect to the sale of 8,500,000 Ordinary Shares (equivalent to 4,250,000 ADSs) in the Offering, the undersigned's Retained Shares shall consist of 39,445,000 Ordinary Shares, representing approximately 16.1% of the 245,000,000 Ordinary Shares expected to be outstanding on a post-Offering basis (assuming no exercise of the over-allotment option).]

[For Kestrel Capital Partners AG: As of the date hereof, the undersigned beneficially owns 20,855,000 Ordinary Shares. After giving effect to the sale of 4,300,000 Ordinary Shares (equivalent to 2,150,000 ADSs) in the Offering, the undersigned's Retained Shares shall consist of 16,555,000 Ordinary Shares, representing approximately 6.8% of the 245,000,000 Ordinary Shares expected to be outstanding on a post-Offering basis (assuming no exercise of the over-allotment option).]

"Representative" means Westbridge Securities LLC, in its capacity as representative of the several Underwriters in connection with the Offering.

"Transfer" has the meaning set forth in Section 2 of this Lock-Up Letter.

Capitalized terms used but not otherwise defined in this Lock-Up Letter shall have the meanings ascribed to such terms in the Underwriting Agreement.

Section 2. Lock-Up Restrictions

During the Lock-Up Period, the undersigned agrees that it will not, without the prior written consent of the Representative, directly or indirectly:

(a) offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale of, or otherwise transfer or dispose of any Lock-Up Securities, or any interest therein;

(b) enter into any swap, hedge, forward, future, cap, collar, or other arrangement or agreement that transfers to another, in whole or in part, any of the economic consequences of ownership of any Lock-Up Securities, whether any such transaction described in this clause (b) is to be settled by delivery of Ordinary Shares, ADSs, or other securities, in cash, or otherwise;

(c) make any demand for, or exercise any right with respect to, the registration of any Lock-Up Securities under the Securities Act or under any securities laws of any other jurisdiction, including, without limitation, the laws of the Federal Republic of Germany, any member state of the European Union, or Switzerland;

(d) deposit any Ordinary Shares into any depositary receipt facility, including, without limitation, the facility maintained by the Depositary (Meridian Trust Company, N.A.) for the issuance of ADSs, during the Lock-Up Period, except in connection with the Offering itself and except for any deposit of Ordinary Shares into such facility in connection with a transfer that is otherwise permitted under Section 3 of this Lock-Up Letter; or

(e) publicly disclose the intention to do any of the foregoing.

For purposes of this Lock-Up Letter, the term "Transfer" means any sale, assignment, transfer, pledge, hypothecation, encumbrance, gift, bequest, donation, or other disposition, whether voluntary or involuntary, whether by operation of law or otherwise, and whether effected on or off a securities exchange, including, without limitation, on the Nasdaq Global Select Market, the Frankfurt Stock Exchange (Frankfurter Wertpapierbörse), or any other regulated market, multilateral trading facility, or organized trading facility, and includes, without limitation, any disposition by way of short sale, option, futures contract, swap, forward contract, or other derivative transaction, any transfer of record or beneficial ownership, any transfer to a trustee, custodian, or nominee, and any transfer pursuant to a pledge, margin arrangement, or lending arrangement. For the avoidance of doubt, the restrictions set forth in this Section 2 apply regardless of whether the Transfer would be effected in a transaction subject to the laws of the United States, the Federal Republic of Germany, Switzerland, the European Union, or any other jurisdiction.

Section 3. Permitted Exceptions

Notwithstanding the restrictions set forth in Section 2 of this Lock-Up Letter, the undersigned may effect the following transactions without the prior written consent of the Representative:

(a) Transfers Pursuant to the Underwriting Agreement. The sale of Ordinary Shares (in the form of ADSs) by the undersigned in the Offering pursuant to and in accordance with the terms of the Underwriting Agreement.

(b) Transfers to Affiliates. Transfers of any Lock-Up Securities to any wholly-owned subsidiary (Tochtergesellschaft) of the undersigned, or to any entity that directly or indirectly controls, is controlled by, or is under common control with, the undersigned (within the meaning of Rule 405 under the Securities Act); provided, that as a precondition to any such transfer, such transferee shall execute and deliver to the Representative a lock-up letter substantially in the form of this Lock-Up Letter (or in the form of Exhibit A hereto) agreeing to be bound by the restrictions set forth herein for the remainder of the Lock-Up Period as if such transferee were the undersigned hereunder.

(c) Distributions to Partners, Members, or Shareholders. Distributions by the undersigned (if the undersigned is a partnership, limited liability company, Gesellschaft mit beschränkter Haftung, Kommanditgesellschaft, or similar entity) of any Lock-Up Securities to its partners, members, or shareholders, as applicable; provided, that as a precondition to any such distribution, each recipient of such distribution (each, a "distributee") shall execute and deliver to the Representative a lock-up letter substantially in the form of this Lock-Up Letter (or in the form of Exhibit A hereto) agreeing to be bound by the restrictions set forth herein for the remainder of the Lock-Up Period as if such distributee were the undersigned hereunder.

(d) Transfers by Operation of Law. Transfers of any Lock-Up Securities occurring by operation of law, including, without limitation, pursuant to any order of a court or regulatory authority of competent jurisdiction (e.g., in connection with a bankruptcy (Insolvenz) or insolvency proceeding under the German Insolvency Code (Insolvenzordnung), Swiss debt enforcement and bankruptcy law (Bundesgesetz über Schuldbetreibung und Konkurs), or under the laws of any other jurisdiction); provided, that the undersigned shall use commercially reasonable efforts to cause any transferee acquiring Lock-Up Securities pursuant to this clause (d) to execute and deliver to the Representative a lock-up letter substantially in the form of this Lock-Up Letter (or in the form of Exhibit A hereto) agreeing to be bound by the restrictions set forth herein for the remainder of the Lock-Up Period.

(e) Transfers Pursuant to a Bona Fide Third-Party Tender Offer, Merger, Consolidation, or Other Similar Transaction. Transfers of any Lock-Up Securities made in connection with a bona fide third-party tender offer for all or substantially all of the Company's outstanding Ordinary Shares, or a merger (Verschmelzung), consolidation, or other similar business combination (Unternehmensverbindung) involving the Company that has been approved by the Supervisory Board (Aufsichtsrat) of the Company, and that, in any such case, is made to all holders of Ordinary Shares of the Company on the same terms; provided, that in the event such tender offer, merger, consolidation, or other similar transaction is not completed, all Lock-Up Securities owned by the undersigned shall remain subject to the restrictions set forth in Section 2 of this Lock-Up Letter for the remainder of the Lock-Up Period.

(f) Establishment of a Trading Plan. The establishment by the undersigned of a written trading plan that meets the requirements of Rule 10b5-1 under the Exchange Act for the transfer of Lock-Up Securities; provided, that (i) no sales, transfers, or other dispositions of Lock-Up Securities may be made under such plan during the Lock-Up Period, and (ii) no public announcement, filing, or disclosure shall be required or voluntarily made by or on behalf of the undersigned regarding the establishment of such plan during the Lock-Up Period.

In each case described in clauses (b) through (f) above involving a transfer of Lock-Up Securities to a permitted transferee, no filing under Section 16(a) of the Exchange Act, no filing or notification under Regulation (EU) No. 596/2014 of the European Parliament and of the Council of April 16, 2014 on market abuse (the "Market Abuse Regulation" or "MAR"), and no other public filing, announcement, or disclosure shall be required or voluntarily made in connection with such transfer during the Lock-Up Period; provided, however, that if any such filing, announcement, or disclosure is required by applicable law, rule, or regulation (including, without limitation, mandatory notifications under Article 19 of MAR or Section 16(a) of the Exchange Act), then such filing, announcement, or disclosure shall clearly indicate in the footnotes thereto (or, in the case of a notification under MAR, in the narrative section thereof) that the transfer is being made pursuant to a permitted exception under a lock-up agreement entered into in connection with the initial public offering of the Company's ADSs and that the transferee is bound by the terms of such lock-up agreement for the remainder of the applicable lock-up period.

Section 4. Representative's Consent; Waiver

The Representative may, in its sole and absolute discretion, at any time and from time to time during the Lock-Up Period, release all or any portion of the Lock-Up Securities from the restrictions set forth in Section 2 of this Lock-Up Letter. Any such release or waiver shall be effective only if delivered in writing (including by email transmission to the undersigned's counsel) by the Representative to the undersigned (or its legal counsel), and any oral statements or communications regarding any proposed release or waiver shall be of no force or effect.

The undersigned acknowledges and agrees that, if the Representative grants a release or waiver of the lock-up restrictions applicable to any other selling shareholder, officer, director, or other security holder of the Company that is subject to a lock-up agreement or lock-up letter entered into in connection with the Offering, such release or waiver shall not create any obligation on the part of the Representative to grant any similar or corresponding release or waiver to the undersigned, whether on the same terms, pro rata, or otherwise.

No consideration shall be required from the undersigned, the Company, or any other person in exchange for any release or waiver granted by the Representative under this Section 4. The decision to grant or withhold consent, or to release or waive any restrictions, shall rest entirely with the Representative and shall not be subject to challenge by the undersigned.

Section 5. Stop Transfer Instructions

The undersigned hereby agrees and consents to the entry of stop transfer instructions with the Company's share registrar, the Depositary (Meridian Trust Company, N.A.), the transfer agent (Crestfield Transfer Services Inc.), and/or any other applicable custodian or nominee holder, against the transfer of any Lock-Up Securities during the Lock-Up Period, except in compliance with the terms of this Lock-Up Letter. The Company is hereby irrevocably authorized and directed by the undersigned to give such stop transfer instructions to the share registrar, the Depositary, the transfer agent, and any other applicable custodian or nominee holder, and the undersigned acknowledges that this Lock-Up Letter constitutes an irrevocable instruction to the Company, the Depositary, and the transfer agent for such purposes. The undersigned further agrees that it shall not seek to circumvent the stop transfer instructions by directing any broker, dealer, custodian, or other intermediary to effect a Transfer of Lock-Up Securities during the Lock-Up Period in contravention of this Lock-Up Letter.

Section 6. Representations and Warranties of the Undersigned

The undersigned hereby represents and warrants to the Representative and each of the Underwriters as follows:

(a) Power and Authority. The undersigned has full corporate or other organizational power and authority to execute, deliver, and perform its obligations under this Lock-Up Letter. The execution, delivery, and performance of this Lock-Up Letter have been duly authorized by all necessary corporate or other organizational action on the part of the undersigned.

(b) Due Organization.

[For Rheintal Industrieholding GmbH: The undersigned is a Gesellschaft mit beschränkter Haftung (GmbH) duly organized and validly existing under the laws of the Federal Republic of Germany, with its registered office at Königsallee 60, 40212 Düsseldorf, Germany. Margarethe Wendt, in her capacity as Managing Director (Geschäftsführerin) of the undersigned, has been duly authorized by all necessary corporate action, including any required approvals of the shareholders' meeting (Gesellschafterversammlung), to execute and deliver this Lock-Up Letter on behalf of the undersigned and to bind the undersigned to the obligations set forth herein.]

[For Kestrel Capital Partners AG: The undersigned is an Aktiengesellschaft (AG) duly organized and validly existing under the laws of Switzerland, with its registered office at Bahnhofstrasse 36, 8001 Glenrock Assurance, Switzerland. Henrik Sørensen, in his capacity as Managing Partner of the undersigned, has been duly authorized by all necessary corporate action, including any required approvals of the board of directors (Verwaltungsrat), to execute and deliver this Lock-Up Letter on behalf of the undersigned and to bind the undersigned to the obligations set forth herein.]

(c) Valid and Binding Obligation. This Lock-Up Letter has been duly executed and delivered by the undersigned and constitutes the valid and binding obligation of the undersigned, enforceable against the undersigned in accordance with its terms, subject to applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance, and other similar laws affecting creditors' rights and remedies generally, and subject, as to enforceability, to general principles of equity, including principles of commercial reasonableness, good faith, and fair dealing (regardless of whether enforcement is sought in a proceeding at law or in equity).

(d) No Conflicts. The execution, delivery, and performance of this Lock-Up Letter by the undersigned will not (i) conflict with, result in a breach or violation of, or constitute a default under (or an event that, with the giving of notice or the lapse of time or both, would constitute a default under) the undersigned's organizational documents (Satzung, articles of association, partnership agreement, or equivalent), (ii) conflict with or violate any applicable law, statute, rule, regulation, order, judgment, injunction, or decree of any governmental authority or regulatory body binding upon the undersigned, or (iii) conflict with, result in a breach of, or constitute a default under any contract, agreement, indenture, lease, permit, or other instrument to which the undersigned is a party or by which the undersigned or any of its properties or assets are bound.

(e) Schedule A. Schedule A attached hereto sets forth a true, correct, and complete list of all Lock-Up Securities beneficially owned by the undersigned as of the date hereof, including the number of Ordinary Shares and ADSs (if any), the record holder or registered name of each such security, and the manner in which each such security is held (e.g., directly, through a nominee, through a trust, or through a custodian).

Section 7. No Additional Shares

During the Lock-Up Period, the undersigned agrees that it will not acquire, directly or indirectly, any additional Ordinary Shares of the Company or ADSs, or any securities convertible into or exercisable or exchangeable for Ordinary Shares or ADSs, whether through open market purchases, privately negotiated transactions, or otherwise, except for Ordinary Shares or ADSs that may be received by the undersigned pursuant to stock dividends (Gratisaktien), stock splits (Aktiensplit), recapitalizations, or other similar corporate actions that are applicable to all holders of Ordinary Shares on a pro rata basis and do not require any affirmative action by the undersigned to acquire such securities. Any Ordinary Shares, ADSs, or other securities acquired by the undersigned during the Lock-Up Period in contravention of this Section 7 shall be deemed Lock-Up Securities subject to all restrictions set forth in Section 2 of this Lock-Up Letter.

Section 8. Specific Performance; Remedies

The undersigned acknowledges and agrees that (a) the Representative and each of the Underwriters would suffer irreparable harm in the event of any breach or threatened breach by the undersigned of any of the terms, conditions, or obligations set forth in this Lock-Up Letter, (b) monetary damages alone would not constitute an adequate remedy for any such breach or threatened breach, and (c) each of the Representative and the Underwriters shall be entitled to seek and obtain specific performance, injunctive relief, or other equitable remedies (including temporary restraining orders, preliminary injunctions, and permanent injunctions) in any court of competent jurisdiction, in addition to any other remedies available at law or in equity, without the necessity of (i) proving actual damages, (ii) posting any bond or other security, or (iii) establishing the inadequacy of monetary damages. Such equitable remedies shall be cumulative and shall not be deemed to be exclusive of any other remedies to which the Representative or any Underwriter may be entitled at law or in equity or under any other agreement, instrument, or document.

Section 9. Governing Law and Jurisdiction

This Lock-Up Letter shall be governed by, and construed and enforced in accordance with, the laws of the State of New York applicable to agreements made and to be performed entirely within such state, without regard to the conflict-of-laws principles thereof that would result in the application of the laws of any other jurisdiction.

The undersigned hereby irrevocably and unconditionally submits, for itself and its property, to the exclusive jurisdiction of the United States District Court for the Southern District of New York and any New York State court sitting in the Borough of Manhattan, City of New York, New York (and any appellate courts thereof), for the purpose of any suit, action, or proceeding arising out of or relating to this Lock-Up Letter or the transactions contemplated hereby (each, a "Proceeding"), and agrees not to commence any Proceeding except in such courts. The undersigned further agrees that service of any process, summons, notice, or document by registered or certified mail, return receipt requested, addressed to the undersigned at the address set forth below its signature on this Lock-Up Letter (or such other address as the undersigned may specify in writing to the Representative) shall be effective service of process for any Proceeding brought in any such court.

The undersigned hereby irrevocably and unconditionally waives (a) any objection that it may now or hereafter have to the laying of venue of any Proceeding in the courts referred to in this Section 9, and (b) any claim that any Proceeding brought in any such court has been brought in an inconvenient forum.

Section 10. Termination

This Lock-Up Letter shall automatically terminate, and be of no further force or effect, upon the earliest to occur of the following:

(a) the expiration of the Lock-Up Period (i.e., the date that is one hundred and eighty (180) calendar days after the Pricing Date);

(b) written notice delivered by the Company to the Representative that the Company has determined not to proceed with the Offering;

(c) the termination of the Underwriting Agreement (other than those provisions thereof that, by their terms, survive termination) prior to the closing of the Offering and the delivery of and payment for the ADSs, unless the Offering is subsequently consummated pursuant to a replacement or amended underwriting agreement; or

(d) December 31, 2026, if the Registration Statement on Form F-1 relating to the Offering has not been filed with the SEC on or prior to such date.

Upon the termination of this Lock-Up Letter pursuant to this Section 10, all obligations of the undersigned hereunder shall cease and the undersigned shall be released from all restrictions on Transfer set forth herein; provided, however, that the representations and warranties set forth in Section 6 shall survive the termination of this Lock-Up Letter.

Section 11. Miscellaneous Provisions

11.1 Entire Agreement. This Lock-Up Letter constitutes the entire agreement between the undersigned, on the one hand, and the Representative, on the other hand, with respect to the subject matter hereof and supersedes all prior and contemporaneous agreements, understandings, representations, warranties, negotiations, and discussions, whether written or oral, relating to the subject matter hereof.

11.2 Amendments. This Lock-Up Letter may not be amended, modified, supplemented, or waived except by a written instrument duly executed by both the undersigned and the Representative. No failure or delay by the Representative in exercising any right, power, or privilege under this Lock-Up Letter shall operate as a waiver thereof, nor shall any single or partial exercise of any right, power, or privilege preclude any other or further exercise thereof or the exercise of any other right, power, or privilege.

11.3 Successors and Assigns. This Lock-Up Letter and all of the terms, conditions, and provisions hereof shall be binding upon and shall inure to the benefit of the undersigned and the Representative and their respective successors, assigns, heirs, executors, administrators, and personal representatives. The Representative may, without the prior consent of the undersigned, assign its rights under this Lock-Up Letter, in whole or in part, to any successor representative of the Underwriters appointed in connection with the Offering. The undersigned may not assign its obligations under this Lock-Up Letter, in whole or in part, without the prior written consent of the Representative, and any purported assignment without such consent shall be void and of no force or effect.

11.4 Severability. If any provision of this Lock-Up Letter, or the application thereof to any person, entity, or circumstance, is held to be invalid, illegal, or unenforceable in any respect by a court of competent jurisdiction, such invalidity, illegality, or unenforceability shall not affect any other provision of this Lock-Up Letter, and the remaining provisions of this Lock-Up Letter shall remain in full force and effect. In the event any such provision is held to be invalid, illegal, or unenforceable, the parties shall negotiate in good faith to modify such provision to the minimum extent necessary to make it valid, legal, and enforceable, while preserving to the greatest extent possible the original intent and economic effect of such provision.

11.5 Counterparts. This Lock-Up Letter may be executed in one or more counterparts (including by facsimile or portable document format (PDF) transmission or other electronic means of communication), each of which shall be deemed an original and all of which together shall constitute one and the same instrument. Delivery of an executed counterpart of this Lock-Up Letter by facsimile, PDF, or other electronic transmission shall be as effective as delivery of an originally executed counterpart.

11.6 Headings. The section headings used in this Lock-Up Letter are for convenience of reference only and shall not be deemed to constitute a part hereof and shall not affect the meaning or interpretation of any of the terms, conditions, or provisions hereof.

11.7 No Third-Party Beneficiaries. Except as expressly set forth in this Section 11.7, no person or entity other than the undersigned and the Representative shall have any rights or remedies under this Lock-Up Letter. The undersigned acknowledges and agrees that each Underwriter named below is an intended third-party beneficiary of this Lock-Up Letter and shall be entitled to enforce the terms and provisions hereof as if such Underwriter were a party hereto:

• Westbridge Securities LLC

• Pinnacle Morgan & Co., Inc.

• Andover Barcliffe Group Inc.

• Northpointe Capital LLC

11.8 Waiver of Jury Trial. EACH OF THE UNDERSIGNED AND THE REPRESENTATIVE HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY SUIT, ACTION, OR PROCEEDING ARISING OUT OF OR RELATING TO THIS LOCK-UP LETTER OR THE TRANSACTIONS CONTEMPLATED HEREBY. EACH PARTY CERTIFIES THAT NO REPRESENTATIVE, AGENT, OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT, IN THE EVENT OF ANY SUCH SUIT, ACTION, OR PROCEEDING, SEEK TO ENFORCE THE FOREGOING WAIVER. EACH PARTY ACKNOWLEDGES THAT IT HAS BEEN INDUCED TO ENTER INTO THIS LOCK-UP LETTER BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION 11.8.

[Remainder of page intentionally left blank. Signature page follows.]

SIGNATURE PAGE TO LOCK-UP LETTER

Very truly yours,

[For Rheintal Industrieholding GmbH:]

RHEINTAL INDUSTRIEHOLDING GESELLSCHAFT MIT BESCHRÄNKTER HAFTUNG

By: ________

Name: Margarethe Wendt

Title: Managing Director (Geschäftsführerin)

Address:

Königsallee 60 40212 Düsseldorf Federal Republic of Germany

[For Kestrel Capital Partners AG:]

KESTREL CAPITAL PARTNERS AKTIENGESELLSCHAFT

By: ________

Name: Henrik Sørensen

Title: Managing Partner

Address:

Bahnhofstrasse 36 8001 Glenrock Assurance Switzerland

ACKNOWLEDGED AND AGREED

WESTBRIDGE SECURITIES LLC, as Representative of the several Underwriters

By: ________

Name: Jonathan Hartwell

Title: Managing Director, Global Equity Capital Markets

Address:

383 Madison Avenue New York, NY 10179 United States of America

SCHEDULE A

LOCK-UP SECURITIES

The undersigned hereby certifies that, as of the date of this Lock-Up Letter, the Lock-Up Securities beneficially owned by the undersigned are as set forth in the table below. This schedule includes all Ordinary Shares, ADSs, options, warrants, and other derivative securities beneficially owned by the undersigned, whether held directly or through trusts, nominees, custodians, or other intermediaries.

[For Rheintal Industrieholding GmbH:]

Pre-Offering ownership: 47,945,000 Ordinary Shares, representing approximately 22.3% of 215,000,000 Ordinary Shares outstanding prior to the Offering.

Post-Offering ownership (Retained Shares): 39,445,000 Ordinary Shares, representing approximately 16.1% of 245,000,000 Ordinary Shares expected to be outstanding following the Offering (assuming no exercise of the over-allotment option).

[For Kestrel Capital Partners AG:]

Pre-Offering ownership: 20,855,000 Ordinary Shares, representing approximately 9.7% of 215,000,000 Ordinary Shares outstanding prior to the Offering.

Post-Offering ownership (Retained Shares): 16,555,000 Ordinary Shares, representing approximately 6.8% of 245,000,000 Ordinary Shares expected to be outstanding following the Offering (assuming no exercise of the over-allotment option).

Instruction to Selling Shareholder: The selling shareholder must list in this Schedule A all Ordinary Shares, ADSs, options, warrants, and other derivative securities beneficially owned by the selling shareholder, including any securities held through trusts, nominees, custodians, or other intermediaries. If any Lock-Up Securities are held through an entity controlled by the selling shareholder, the name of such entity and the number of securities held thereby must be separately identified. If the selling shareholder does not hold any securities of a particular type, indicate "None" in the applicable row.

EXHIBIT A

FORM OF TRANSFEREE LOCK-UP LETTER

[Date]

Westbridge Securities LLC as Representative of the several Underwriters 383 Madison Avenue New York, NY 10179

Attention: Jonathan Hartwell, Managing Director, Global Equity Capital Markets

Re: Lock-Up Letter — Permitted Transferee Joinder — Halcyon Semiconductor Aktiengesellschaft

Ladies and Gentlemen:

The undersigned is a permitted transferee of [●] ordinary shares (Stammaktien), no par value, of Halcyon Semiconductor Aktiengesellschaft, a German stock corporation (Aktiengesellschaft) organized and existing under the laws of the Federal Republic of Germany, registered with the Commercial Register (Handelsregister) of the Local Court (Amtsgericht) of Munich under registration number HRB 217458 (the "Company"), and/or [●] American Depositary Shares ("ADSs"), each representing two (2) ordinary shares of the Company (collectively, the "Transferred Securities"), received from [Name of Transferor] (the "Transferor") on [Date of Transfer] pursuant to Section 3([●]) of that certain Lock-Up Letter, dated [●], 2026 (the "Original Lock-Up Letter"), executed by the Transferor in favor of Westbridge Securities LLC, as Representative of the several Underwriters (the "Representative"), in connection with the initial public offering of ADSs of the Company.

In consideration of the transfer of the Transferred Securities to the undersigned, and as a condition to such transfer, the undersigned hereby agrees to be bound by all of the terms, conditions, restrictions, and obligations set forth in the Original Lock-Up Letter (a copy of which is attached hereto and incorporated herein by reference) with respect to the Transferred Securities, as if the undersigned were the original signatory thereto, for the remainder of the Lock-Up Period (as defined in the Original Lock-Up Letter). Without limiting the generality of the foregoing, the undersigned agrees as follows:

1. During the remainder of the Lock-Up Period, the undersigned will not, without the prior written consent of the Representative, directly or indirectly: (a) offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale of, or otherwise transfer or dispose of any of the Transferred Securities, or any interest therein; (b) enter into any swap, hedge, or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any of the Transferred Securities, whether any such transaction is to be settled by delivery of ordinary shares, ADSs, or other securities, in cash, or otherwise; (c) make any demand for, or exercise any right with respect to, the registration of any of the Transferred Securities under the Securities Act of 1933, as amended, or under any securities laws of any other jurisdiction; (d) deposit any ordinary shares into any depositary receipt facility during the Lock-Up Period; or (e) publicly disclose the intention to do any of the foregoing.

2. The undersigned is entitled to the same permitted exceptions set forth in Section 3 of the Original Lock-Up Letter, subject to the same conditions (including the requirement that any subsequent permitted transferee execute and deliver a lock-up letter in the form of this letter).

3. The undersigned represents and warrants that (a) the undersigned has full power and authority to execute and deliver this letter and to perform its obligations hereunder, (b) this letter has been duly executed and delivered and constitutes a valid and binding obligation of the undersigned, enforceable in accordance with its terms, and (c) the execution, delivery, and performance of this letter will not conflict with or violate any law, regulation, order, or agreement binding upon the undersigned.

4. The undersigned acknowledges and agrees that the Representative and each of the Underwriters would be irreparably harmed by any breach of this letter and that the Representative and the Underwriters shall be entitled to seek specific performance, injunctive relief, or other equitable remedies without the necessity of proving actual damages or posting any bond, in addition to any other remedies available at law or in equity.

5. This letter shall be governed by and construed in accordance with the laws of the State of New York, without regard to its conflict-of-laws principles. The undersigned irrevocably submits to the exclusive jurisdiction of the federal and state courts located in the Borough of Manhattan, City of New York, New York, for any suit, action, or proceeding arising out of or relating to this letter, and irrevocably waives any objection to venue in such courts and any claim of inconvenient forum.

6. WAIVER OF JURY TRIAL. THE UNDERSIGNED HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY SUIT, ACTION, OR PROCEEDING ARISING OUT OF OR RELATING TO THIS LETTER.

This letter shall terminate upon the expiration of the Lock-Up Period or upon the earlier termination of the Original Lock-Up Letter in accordance with Section 10 thereof.

[Remainder of page intentionally left blank. Signature page follows.]

Very truly yours,

[NAME OF PERMITTED TRANSFEREE]

By: ________

Name:

Title:

Address:

Acknowledged:

WESTBRIDGE SECURITIES LLC, as Representative of the several Underwriters

By: ________

Name: Jonathan Hartwell

Title: Managing Director, Global Equity Capital Markets

Attachment: Copy of Original Lock-Up Letter dated [●], 2026

Type of Security	Number of Securities	Record Holder / Registered Name	Manner of Holding
Ordinary Shares (Stammaktien) — Pre-Offering	47,945,000	Rheintal Industrieholding GmbH	Direct (registered in share register of the Company)
Ordinary Shares to be sold in Offering (as ADSs)	(8,500,000) / 4,250,000 ADSs	Rheintal Industrieholding GmbH (to be deposited with Meridian Trust Company, N.A.)	N/A — to be transferred in Offering
Retained Shares (Lock-Up Securities)	39,445,000 Ordinary Shares	Rheintal Industrieholding GmbH	Direct
Options / Warrants / Convertible Securities	None	N/A	N/A
Type of Security	Number of Securities	Record Holder / Registered Name	Manner of Holding
Ordinary Shares (Stammaktien) — Pre-Offering	20,855,000	Kestrel Capital Partners AG	Direct (registered in share register of the Company)
Ordinary Shares to be sold in Offering (as ADSs)	(4,300,000) / 2,150,000 ADSs	Kestrel Capital Partners AG (to be deposited with Meridian Trust Company, N.A.)	N/A — to be transferred in Offering
Retained Shares (Lock-Up Securities)	16,555,000 Ordinary Shares	Kestrel Capital Partners AG	Direct
Options / Warrants / Convertible Securities	None	N/A	N/A

CONFIDENTIAL — DRAFT FOR DISCUSSION PURPOSES ONLY
FORM OF SELLING SHAREHOLDER LOCK-UP LETTER
(To be printed on the letterhead of the applicable selling shareholder — Rheintal Industrieholding GmbH or Kestrel Capital Partners AG)
[●], 2026
Westbridge Securities LLC as Representative of the several Underwriters 383 Madison Avenue New York, NY 10179
Attention: Jonathan Hartwell, Managing Director, Global Equity Capital Markets
Re: Proposed Initial Public Offering of American Depositary Shares of Halcyon Semiconductor Aktiengesellschaft
Ladies and Gentlemen:
The undersigned understands that Westbridge Securities LLC ("Westbridge" or the "Representative") proposes to enter into an underwriting agreement (the "Underwriting Agreement") with Halcyon Semiconductor Aktiengesellschaft, a German stock corporation (Aktiengesellschaft) organized and existing under the laws of the Federal Republic of Germany, with its registered office in Munich, Bavaria, Federal Republic of Germany, registered with the Commercial Register (Handelsregister) of the Local Court (Amtsgericht) of Munich under registration number HRB 217458 (the "Company"), the selling shareholders named therein, and the several underwriters named in Schedule I thereto (collectively, the "Underwriters"), for whom Westbridge is acting as representative, providing for the public offering (the "Offering") of American Depositary Shares ("ADSs") of the Company, each ADS representing two (2) ordinary shares (Stammaktien), no par value (Stückaktien), of the Company (the "Ordinary Shares"). The ADSs are to be issued pursuant to a deposit agreement (the "Deposit Agreement") among the Company, Meridian Trust Company, N.A., as depositary (the "Depositary"), and the holders and beneficial owners of ADSs from time to time. The Company intends to file a Registration Statement on Form F-1 (the "Registration Statement") with the United States Securities and Exchange Commission (the "SEC") under the Securities Act of 1933, as amended (the "Securities Act"), in connection with the Offering, and to apply to list the ADSs on the Nasdaq Global Select Market under the ticker symbol "HCYN."
The undersigned further understands that the Company and the selling shareholders intend to sell in the Offering a number of ADSs to be agreed upon with the Underwriters, consisting of both newly issued Ordinary Shares (in the form of ADSs) by the Company and existing Ordinary Shares (in the form of ADSs) by the selling shareholders, all on the terms and subject to the conditions set forth in the Underwriting Agreement.
The undersigned is a selling shareholder who will sell [●] Ordinary Shares, equivalent to [●] ADSs, in the Offering pursuant to the Underwriting Agreement. Specifically:
[For Rheintal Industrieholding GmbH: The undersigned will sell 8,500,000 Ordinary Shares (equivalent to 4,250,000 ADSs) in the Offering.]
[For Kestrel Capital Partners AG: The undersigned will sell 4,300,000 Ordinary Shares (equivalent to 2,150,000 ADSs) in the Offering.]
The undersigned acknowledges that the Underwriters are entering into the Underwriting Agreement, and proceeding with the Offering, in reliance upon this lock-up letter (this "Lock-Up Letter") as a material inducement, and that the agreements and obligations of the undersigned set forth herein are an essential condition to the willingness of the Underwriters to proceed with the Offering. In consideration of the foregoing, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned hereby agrees as follows:
Section 1. Definitions
As used in this Lock-Up Letter, the following terms shall have the meanings set forth below:
"Lock-Up Period" means the period beginning on the date of the final prospectus relating to the Offering, as filed with the SEC pursuant to Rule 424(b) under the Securities Act (such date, the "Pricing Date," which is currently targeted for on or about July 1, 2026), and continuing through and including the date that is one hundred and eighty (180) calendar days after the Pricing Date (currently targeted for on or about December 28, 2026). For the avoidance of doubt, the Lock-Up Period shall commence on the Pricing Date regardless of whether the Pricing Date is later than the date of this Lock-Up Letter.
"Lock-Up Securities" means (i) all Ordinary Shares of the Company beneficially owned (as determined in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and the rules and regulations promulgated thereunder) by the undersigned as of the date hereof or acquired by the undersigned during the Lock-Up Period, (ii) all ADSs beneficially owned by the undersigned as of the date hereof or acquired by the undersigned during the Lock-Up Period, and (iii) any securities convertible into or exercisable or exchangeable for Ordinary Shares or ADSs beneficially owned by the undersigned as of the date hereof or acquired by the undersigned during the Lock-Up Period, in each case including, without limitation:
(a) Ordinary Shares directly held of record by the undersigned;
(b) ADSs directly held of record by the undersigned;
(c) Ordinary Shares or ADSs held by or through any trust, partnership, limited liability company (Gesellschaft mit beschränkter Haftung or Kommanditgesellschaft), or other entity directly or indirectly controlled by the undersigned;
(d) any options, warrants, rights, or other securities convertible into or exercisable or exchangeable for Ordinary Shares or ADSs, whether or not vested or currently exercisable; and
(e) any Ordinary Shares or ADSs acquired by the undersigned during the Lock-Up Period, whether through open market purchases, private transactions, the exercise of options or warrants, the conversion or exchange of convertible securities, or otherwise.
Notwithstanding the foregoing, Lock-Up Securities shall not include any Ordinary Shares (or ADSs representing such Ordinary Shares) being sold by the undersigned in the Offering pursuant to the Underwriting Agreement (i.e., 8,500,000 Ordinary Shares in the case of Rheintal Industrieholding GmbH, or 4,300,000 Ordinary Shares in the case of Kestrel Capital Partners AG, as applicable).
"Retained Shares" means all Ordinary Shares and ADSs beneficially owned by the undersigned after giving effect to the sale of Ordinary Shares (in the form of ADSs) in the Offering.
[For Rheintal Industrieholding GmbH: As of the date hereof, the undersigned beneficially owns 47,945,000 Ordinary Shares. After giving effect to the sale of 8,500,000 Ordinary Shares (equivalent to 4,250,000 ADSs) in the Offering, the undersigned's Retained Shares shall consist of 39,445,000 Ordinary Shares, representing approximately 16.1% of the 245,000,000 Ordinary Shares expected to be outstanding on a post-Offering basis (assuming no exercise of the over-allotment option).]
[For Kestrel Capital Partners AG: As of the date hereof, the undersigned beneficially owns 20,855,000 Ordinary Shares. After giving effect to the sale of 4,300,000 Ordinary Shares (equivalent to 2,150,000 ADSs) in the Offering, the undersigned's Retained Shares shall consist of 16,555,000 Ordinary Shares, representing approximately 6.8% of the 245,000,000 Ordinary Shares expected to be outstanding on a post-Offering basis (assuming no exercise of the over-allotment option).]
"Representative" means Westbridge Securities LLC, in its capacity as representative of the several Underwriters in connection with the Offering.
"Transfer" has the meaning set forth in Section 2 of this Lock-Up Letter.
Capitalized terms used but not otherwise defined in this Lock-Up Letter shall have the meanings ascribed to such terms in the Underwriting Agreement.
Section 2. Lock-Up Restrictions
During the Lock-Up Period, the undersigned agrees that it will not, without the prior written consent of the Representative, directly or indirectly:
(a) offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale of, or otherwise transfer or dispose of any Lock-Up Securities, or any interest therein;
(b) enter into any swap, hedge, forward, future, cap, collar, or other arrangement or agreement that transfers to another, in whole or in part, any of the economic consequences of ownership of any Lock-Up Securities, whether any such transaction described in this clause (b) is to be settled by delivery of Ordinary Shares, ADSs, or other securities, in cash, or otherwise;
(c) make any demand for, or exercise any right with respect to, the registration of any Lock-Up Securities under the Securities Act or under any securities laws of any other jurisdiction, including, without limitation, the laws of the Federal Republic of Germany, any member state of the European Union, or Switzerland;
(d) deposit any Ordinary Shares into any depositary receipt facility, including, without limitation, the facility maintained by the Depositary (Meridian Trust Company, N.A.) for the issuance of ADSs, during the Lock-Up Period, except in connection with the Offering itself and except for any deposit of Ordinary Shares into such facility in connection with a transfer that is otherwise permitted under Section 3 of this Lock-Up Letter; or
(e) publicly disclose the intention to do any of the foregoing.
For purposes of this Lock-Up Letter, the term "Transfer" means any sale, assignment, transfer, pledge, hypothecation, encumbrance, gift, bequest, donation, or other disposition, whether voluntary or involuntary, whether by operation of law or otherwise, and whether effected on or off a securities exchange, including, without limitation, on the Nasdaq Global Select Market, the Frankfurt Stock Exchange (Frankfurter Wertpapierbörse), or any other regulated market, multilateral trading facility, or organized trading facility, and includes, without limitation, any disposition by way of short sale, option, futures contract, swap, forward contract, or other derivative transaction, any transfer of record or beneficial ownership, any transfer to a trustee, custodian, or nominee, and any transfer pursuant to a pledge, margin arrangement, or lending arrangement. For the avoidance of doubt, the restrictions set forth in this Section 2 apply regardless of whether the Transfer would be effected in a transaction subject to the laws of the United States, the Federal Republic of Germany, Switzerland, the European Union, or any other jurisdiction.
Section 3. Permitted Exceptions
Notwithstanding the restrictions set forth in Section 2 of this Lock-Up Letter, the undersigned may effect the following transactions without the prior written consent of the Representative:
(a) Transfers Pursuant to the Underwriting Agreement. The sale of Ordinary Shares (in the form of ADSs) by the undersigned in the Offering pursuant to and in accordance with the terms of the Underwriting Agreement.
(b) Transfers to Affiliates. Transfers of any Lock-Up Securities to any wholly-owned subsidiary (Tochtergesellschaft) of the undersigned, or to any entity that directly or indirectly controls, is controlled by, or is under common control with, the undersigned (within the meaning of Rule 405 under the Securities Act); provided, that as a precondition to any such transfer, such transferee shall execute and deliver to the Representative a lock-up letter substantially in the form of this Lock-Up Letter (or in the form of Exhibit A hereto) agreeing to be bound by the restrictions set forth herein for the remainder of the Lock-Up Period as if such transferee were the undersigned hereunder.
(c) Distributions to Partners, Members, or Shareholders. Distributions by the undersigned (if the undersigned is a partnership, limited liability company, Gesellschaft mit beschränkter Haftung, Kommanditgesellschaft, or similar entity) of any Lock-Up Securities to its partners, members, or shareholders, as applicable; provided, that as a precondition to any such distribution, each recipient of such distribution (each, a "distributee") shall execute and deliver to the Representative a lock-up letter substantially in the form of this Lock-Up Letter (or in the form of Exhibit A hereto) agreeing to be bound by the restrictions set forth herein for the remainder of the Lock-Up Period as if such distributee were the undersigned hereunder.
(d) Transfers by Operation of Law. Transfers of any Lock-Up Securities occurring by operation of law, including, without limitation, pursuant to any order of a court or regulatory authority of competent jurisdiction (e.g., in connection with a bankruptcy (Insolvenz) or insolvency proceeding under the German Insolvency Code (Insolvenzordnung), Swiss debt enforcement and bankruptcy law (Bundesgesetz über Schuldbetreibung und Konkurs), or under the laws of any other jurisdiction); provided, that the undersigned shall use commercially reasonable efforts to cause any transferee acquiring Lock-Up Securities pursuant to this clause (d) to execute and deliver to the Representative a lock-up letter substantially in the form of this Lock-Up Letter (or in the form of Exhibit A hereto) agreeing to be bound by the restrictions set forth herein for the remainder of the Lock-Up Period.
(e) Transfers Pursuant to a Bona Fide Third-Party Tender Offer, Merger, Consolidation, or Other Similar Transaction. Transfers of any Lock-Up Securities made in connection with a bona fide third-party tender offer for all or substantially all of the Company's outstanding Ordinary Shares, or a merger (Verschmelzung), consolidation, or other similar business combination (Unternehmensverbindung) involving the Company that has been approved by the Supervisory Board (Aufsichtsrat) of the Company, and that, in any such case, is made to all holders of Ordinary Shares of the Company on the same terms; provided, that in the event such tender offer, merger, consolidation, or other similar transaction is not completed, all Lock-Up Securities owned by the undersigned shall remain subject to the restrictions set forth in Section 2 of this Lock-Up Letter for the remainder of the Lock-Up Period.
(f) Establishment of a Trading Plan. The establishment by the undersigned of a written trading plan that meets the requirements of Rule 10b5-1 under the Exchange Act for the transfer of Lock-Up Securities; provided, that (i) no sales, transfers, or other dispositions of Lock-Up Securities may be made under such plan during the Lock-Up Period, and (ii) no public announcement, filing, or disclosure shall be required or voluntarily made by or on behalf of the undersigned regarding the establishment of such plan during the Lock-Up Period.
In each case described in clauses (b) through (f) above involving a transfer of Lock-Up Securities to a permitted transferee, no filing under Section 16(a) of the Exchange Act, no filing or notification under Regulation (EU) No. 596/2014 of the European Parliament and of the Council of April 16, 2014 on market abuse (the "Market Abuse Regulation" or "MAR"), and no other public filing, announcement, or disclosure shall be required or voluntarily made in connection with such transfer during the Lock-Up Period; provided, however, that if any such filing, announcement, or disclosure is required by applicable law, rule, or regulation (including, without limitation, mandatory notifications under Article 19 of MAR or Section 16(a) of the Exchange Act), then such filing, announcement, or disclosure shall clearly indicate in the footnotes thereto (or, in the case of a notification under MAR, in the narrative section thereof) that the transfer is being made pursuant to a permitted exception under a lock-up agreement entered into in connection with the initial public offering of the Company's ADSs and that the transferee is bound by the terms of such lock-up agreement for the remainder of the applicable lock-up period.
Section 4. Representative's Consent; Waiver
The Representative may, in its sole and absolute discretion, at any time and from time to time during the Lock-Up Period, release all or any portion of the Lock-Up Securities from the restrictions set forth in Section 2 of this Lock-Up Letter. Any such release or waiver shall be effective only if delivered in writing (including by email transmission to the undersigned's counsel) by the Representative to the undersigned (or its legal counsel), and any oral statements or communications regarding any proposed release or waiver shall be of no force or effect.
The undersigned acknowledges and agrees that, if the Representative grants a release or waiver of the lock-up restrictions applicable to any other selling shareholder, officer, director, or other security holder of the Company that is subject to a lock-up agreement or lock-up letter entered into in connection with the Offering, such release or waiver shall not create any obligation on the part of the Representative to grant any similar or corresponding release or waiver to the undersigned, whether on the same terms, pro rata, or otherwise.
No consideration shall be required from the undersigned, the Company, or any other person in exchange for any release or waiver granted by the Representative under this Section 4. The decision to grant or withhold consent, or to release or waive any restrictions, shall rest entirely with the Representative and shall not be subject to challenge by the undersigned.
Section 5. Stop Transfer Instructions
The undersigned hereby agrees and consents to the entry of stop transfer instructions with the Company's share registrar, the Depositary (Meridian Trust Company, N.A.), the transfer agent (Crestfield Transfer Services Inc.), and/or any other applicable custodian or nominee holder, against the transfer of any Lock-Up Securities during the Lock-Up Period, except in compliance with the terms of this Lock-Up Letter. The Company is hereby irrevocably authorized and directed by the undersigned to give such stop transfer instructions to the share registrar, the Depositary, the transfer agent, and any other applicable custodian or nominee holder, and the undersigned acknowledges that this Lock-Up Letter constitutes an irrevocable instruction to the Company, the Depositary, and the transfer agent for such purposes. The undersigned further agrees that it shall not seek to circumvent the stop transfer instructions by directing any broker, dealer, custodian, or other intermediary to effect a Transfer of Lock-Up Securities during the Lock-Up Period in contravention of this Lock-Up Letter.
Section 6. Representations and Warranties of the Undersigned
The undersigned hereby represents and warrants to the Representative and each of the Underwriters as follows:
(a) Power and Authority. The undersigned has full corporate or other organizational power and authority to execute, deliver, and perform its obligations under this Lock-Up Letter. The execution, delivery, and performance of this Lock-Up Letter have been duly authorized by all necessary corporate or other organizational action on the part of the undersigned.
(b) Due Organization.
[For Rheintal Industrieholding GmbH: The undersigned is a Gesellschaft mit beschränkter Haftung (GmbH) duly organized and validly existing under the laws of the Federal Republic of Germany, with its registered office at Königsallee 60, 40212 Düsseldorf, Germany. Margarethe Wendt, in her capacity as Managing Director (Geschäftsführerin) of the undersigned, has been duly authorized by all necessary corporate action, including any required approvals of the shareholders' meeting (Gesellschafterversammlung), to execute and deliver this Lock-Up Letter on behalf of the undersigned and to bind the undersigned to the obligations set forth herein.]
[For Kestrel Capital Partners AG: The undersigned is an Aktiengesellschaft (AG) duly organized and validly existing under the laws of Switzerland, with its registered office at Bahnhofstrasse 36, 8001 Glenrock Assurance, Switzerland. Henrik Sørensen, in his capacity as Managing Partner of the undersigned, has been duly authorized by all necessary corporate action, including any required approvals of the board of directors (Verwaltungsrat), to execute and deliver this Lock-Up Letter on behalf of the undersigned and to bind the undersigned to the obligations set forth herein.]
(c) Valid and Binding Obligation. This Lock-Up Letter has been duly executed and delivered by the undersigned and constitutes the valid and binding obligation of the undersigned, enforceable against the undersigned in accordance with its terms, subject to applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance, and other similar laws affecting creditors' rights and remedies generally, and subject, as to enforceability, to general principles of equity, including principles of commercial reasonableness, good faith, and fair dealing (regardless of whether enforcement is sought in a proceeding at law or in equity).
(d) No Conflicts. The execution, delivery, and performance of this Lock-Up Letter by the undersigned will not (i) conflict with, result in a breach or violation of, or constitute a default under (or an event that, with the giving of notice or the lapse of time or both, would constitute a default under) the undersigned's organizational documents (Satzung, articles of association, partnership agreement, or equivalent), (ii) conflict with or violate any applicable law, statute, rule, regulation, order, judgment, injunction, or decree of any governmental authority or regulatory body binding upon the undersigned, or (iii) conflict with, result in a breach of, or constitute a default under any contract, agreement, indenture, lease, permit, or other instrument to which the undersigned is a party or by which the undersigned or any of its properties or assets are bound.
(e) Schedule A. Schedule A attached hereto sets forth a true, correct, and complete list of all Lock-Up Securities beneficially owned by the undersigned as of the date hereof, including the number of Ordinary Shares and ADSs (if any), the record holder or registered name of each such security, and the manner in which each such security is held (e.g., directly, through a nominee, through a trust, or through a custodian).
Section 7. No Additional Shares
During the Lock-Up Period, the undersigned agrees that it will not acquire, directly or indirectly, any additional Ordinary Shares of the Company or ADSs, or any securities convertible into or exercisable or exchangeable for Ordinary Shares or ADSs, whether through open market purchases, privately negotiated transactions, or otherwise, except for Ordinary Shares or ADSs that may be received by the undersigned pursuant to stock dividends (Gratisaktien), stock splits (Aktiensplit), recapitalizations, or other similar corporate actions that are applicable to all holders of Ordinary Shares on a pro rata basis and do not require any affirmative action by the undersigned to acquire such securities. Any Ordinary Shares, ADSs, or other securities acquired by the undersigned during the Lock-Up Period in contravention of this Section 7 shall be deemed Lock-Up Securities subject to all restrictions set forth in Section 2 of this Lock-Up Letter.
Section 8. Specific Performance; Remedies
The undersigned acknowledges and agrees that (a) the Representative and each of the Underwriters would suffer irreparable harm in the event of any breach or threatened breach by the undersigned of any of the terms, conditions, or obligations set forth in this Lock-Up Letter, (b) monetary damages alone would not constitute an adequate remedy for any such breach or threatened breach, and (c) each of the Representative and the Underwriters shall be entitled to seek and obtain specific performance, injunctive relief, or other equitable remedies (including temporary restraining orders, preliminary injunctions, and permanent injunctions) in any court of competent jurisdiction, in addition to any other remedies available at law or in equity, without the necessity of (i) proving actual damages, (ii) posting any bond or other security, or (iii) establishing the inadequacy of monetary damages. Such equitable remedies shall be cumulative and shall not be deemed to be exclusive of any other remedies to which the Representative or any Underwriter may be entitled at law or in equity or under any other agreement, instrument, or document.
Section 9. Governing Law and Jurisdiction
This Lock-Up Letter shall be governed by, and construed and enforced in accordance with, the laws of the State of New York applicable to agreements made and to be performed entirely within such state, without regard to the conflict-of-laws principles thereof that would result in the application of the laws of any other jurisdiction.
The undersigned hereby irrevocably and unconditionally submits, for itself and its property, to the exclusive jurisdiction of the United States District Court for the Southern District of New York and any New York State court sitting in the Borough of Manhattan, City of New York, New York (and any appellate courts thereof), for the purpose of any suit, action, or proceeding arising out of or relating to this Lock-Up Letter or the transactions contemplated hereby (each, a "Proceeding"), and agrees not to commence any Proceeding except in such courts. The undersigned further agrees that service of any process, summons, notice, or document by registered or certified mail, return receipt requested, addressed to the undersigned at the address set forth below its signature on this Lock-Up Letter (or such other address as the undersigned may specify in writing to the Representative) shall be effective service of process for any Proceeding brought in any such court.
The undersigned hereby irrevocably and unconditionally waives (a) any objection that it may now or hereafter have to the laying of venue of any Proceeding in the courts referred to in this Section 9, and (b) any claim that any Proceeding brought in any such court has been brought in an inconvenient forum.
Section 10. Termination
This Lock-Up Letter shall automatically terminate, and be of no further force or effect, upon the earliest to occur of the following:
(a) the expiration of the Lock-Up Period (i.e., the date that is one hundred and eighty (180) calendar days after the Pricing Date);
(b) written notice delivered by the Company to the Representative that the Company has determined not to proceed with the Offering;
(c) the termination of the Underwriting Agreement (other than those provisions thereof that, by their terms, survive termination) prior to the closing of the Offering and the delivery of and payment for the ADSs, unless the Offering is subsequently consummated pursuant to a replacement or amended underwriting agreement; or
(d) December 31, 2026, if the Registration Statement on Form F-1 relating to the Offering has not been filed with the SEC on or prior to such date.
Upon the termination of this Lock-Up Letter pursuant to this Section 10, all obligations of the undersigned hereunder shall cease and the undersigned shall be released from all restrictions on Transfer set forth herein; provided, however, that the representations and warranties set forth in Section 6 shall survive the termination of this Lock-Up Letter.
Section 11. Miscellaneous Provisions
11.1 Entire Agreement. This Lock-Up Letter constitutes the entire agreement between the undersigned, on the one hand, and the Representative, on the other hand, with respect to the subject matter hereof and supersedes all prior and contemporaneous agreements, understandings, representations, warranties, negotiations, and discussions, whether written or oral, relating to the subject matter hereof.
11.2 Amendments. This Lock-Up Letter may not be amended, modified, supplemented, or waived except by a written instrument duly executed by both the undersigned and the Representative. No failure or delay by the Representative in exercising any right, power, or privilege under this Lock-Up Letter shall operate as a waiver thereof, nor shall any single or partial exercise of any right, power, or privilege preclude any other or further exercise thereof or the exercise of any other right, power, or privilege.
11.3 Successors and Assigns. This Lock-Up Letter and all of the terms, conditions, and provisions hereof shall be binding upon and shall inure to the benefit of the undersigned and the Representative and their respective successors, assigns, heirs, executors, administrators, and personal representatives. The Representative may, without the prior consent of the undersigned, assign its rights under this Lock-Up Letter, in whole or in part, to any successor representative of the Underwriters appointed in connection with the Offering. The undersigned may not assign its obligations under this Lock-Up Letter, in whole or in part, without the prior written consent of the Representative, and any purported assignment without such consent shall be void and of no force or effect.
11.4 Severability. If any provision of this Lock-Up Letter, or the application thereof to any person, entity, or circumstance, is held to be invalid, illegal, or unenforceable in any respect by a court of competent jurisdiction, such invalidity, illegality, or unenforceability shall not affect any other provision of this Lock-Up Letter, and the remaining provisions of this Lock-Up Letter shall remain in full force and effect. In the event any such provision is held to be invalid, illegal, or unenforceable, the parties shall negotiate in good faith to modify such provision to the minimum extent necessary to make it valid, legal, and enforceable, while preserving to the greatest extent possible the original intent and economic effect of such provision.
11.5 Counterparts. This Lock-Up Letter may be executed in one or more counterparts (including by facsimile or portable document format (PDF) transmission or other electronic means of communication), each of which shall be deemed an original and all of which together shall constitute one and the same instrument. Delivery of an executed counterpart of this Lock-Up Letter by facsimile, PDF, or other electronic transmission shall be as effective as delivery of an originally executed counterpart.
11.6 Headings. The section headings used in this Lock-Up Letter are for convenience of reference only and shall not be deemed to constitute a part hereof and shall not affect the meaning or interpretation of any of the terms, conditions, or provisions hereof.
11.7 No Third-Party Beneficiaries. Except as expressly set forth in this Section 11.7, no person or entity other than the undersigned and the Representative shall have any rights or remedies under this Lock-Up Letter. The undersigned acknowledges and agrees that each Underwriter named below is an intended third-party beneficiary of this Lock-Up Letter and shall be entitled to enforce the terms and provisions hereof as if such Underwriter were a party hereto:
•  Westbridge Securities LLC
•  Pinnacle Morgan & Co., Inc.
•  Andover Barcliffe Group Inc.
•  Northpointe Capital LLC
11.8 Waiver of Jury Trial. EACH OF THE UNDERSIGNED AND THE REPRESENTATIVE HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY SUIT, ACTION, OR PROCEEDING ARISING OUT OF OR RELATING TO THIS LOCK-UP LETTER OR THE TRANSACTIONS CONTEMPLATED HEREBY. EACH PARTY CERTIFIES THAT NO REPRESENTATIVE, AGENT, OR ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD NOT, IN THE EVENT OF ANY SUCH SUIT, ACTION, OR PROCEEDING, SEEK TO ENFORCE THE FOREGOING WAIVER. EACH PARTY ACKNOWLEDGES THAT IT HAS BEEN INDUCED TO ENTER INTO THIS LOCK-UP LETTER BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION 11.8.
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SIGNATURE PAGE TO LOCK-UP LETTER
Very truly yours,
[For Rheintal Industrieholding GmbH:]
RHEINTAL INDUSTRIEHOLDING GESELLSCHAFT MIT BESCHRÄNKTER HAFTUNG
By: ________
Name: Margarethe Wendt
Title: Managing Director (Geschäftsführerin)
Address:
Königsallee 60 40212 Düsseldorf Federal Republic of Germany
[For Kestrel Capital Partners AG:]
KESTREL CAPITAL PARTNERS AKTIENGESELLSCHAFT
By: ________
Name: Henrik Sørensen
Title: Managing Partner
Address:
Bahnhofstrasse 36 8001 Glenrock Assurance Switzerland
ACKNOWLEDGED AND AGREED
WESTBRIDGE SECURITIES LLC, as Representative of the several Underwriters
By: ________
Name: Jonathan Hartwell
Title: Managing Director, Global Equity Capital Markets
Address:
383 Madison Avenue New York, NY 10179 United States of America
SCHEDULE A
LOCK-UP SECURITIES
The undersigned hereby certifies that, as of the date of this Lock-Up Letter, the Lock-Up Securities beneficially owned by the undersigned are as set forth in the table below. This schedule includes all Ordinary Shares, ADSs, options, warrants, and other derivative securities beneficially owned by the undersigned, whether held directly or through trusts, nominees, custodians, or other intermediaries.
[For Rheintal Industrieholding GmbH:]
Pre-Offering ownership: 47,945,000 Ordinary Shares, representing approximately 22.3% of 215,000,000 Ordinary Shares outstanding prior to the Offering.
Post-Offering ownership (Retained Shares): 39,445,000 Ordinary Shares, representing approximately 16.1% of 245,000,000 Ordinary Shares expected to be outstanding following the Offering (assuming no exercise of the over-allotment option).
[For Kestrel Capital Partners AG:]
Pre-Offering ownership: 20,855,000 Ordinary Shares, representing approximately 9.7% of 215,000,000 Ordinary Shares outstanding prior to the Offering.
Post-Offering ownership (Retained Shares): 16,555,000 Ordinary Shares, representing approximately 6.8% of 245,000,000 Ordinary Shares expected to be outstanding following the Offering (assuming no exercise of the over-allotment option).
Instruction to Selling Shareholder: The selling shareholder must list in this Schedule A all Ordinary Shares, ADSs, options, warrants, and other derivative securities beneficially owned by the selling shareholder, including any securities held through trusts, nominees, custodians, or other intermediaries. If any Lock-Up Securities are held through an entity controlled by the selling shareholder, the name of such entity and the number of securities held thereby must be separately identified. If the selling shareholder does not hold any securities of a particular type, indicate "None" in the applicable row.
EXHIBIT A
FORM OF TRANSFEREE LOCK-UP LETTER
[Date]
Westbridge Securities LLC as Representative of the several Underwriters 383 Madison Avenue New York, NY 10179
Attention: Jonathan Hartwell, Managing Director, Global Equity Capital Markets
Re: Lock-Up Letter — Permitted Transferee Joinder — Halcyon Semiconductor Aktiengesellschaft
Ladies and Gentlemen:
The undersigned is a permitted transferee of [●] ordinary shares (Stammaktien), no par value, of Halcyon Semiconductor Aktiengesellschaft, a German stock corporation (Aktiengesellschaft) organized and existing under the laws of the Federal Republic of Germany, registered with the Commercial Register (Handelsregister) of the Local Court (Amtsgericht) of Munich under registration number HRB 217458 (the "Company"), and/or [●] American Depositary Shares ("ADSs"), each representing two (2) ordinary shares of the Company (collectively, the "Transferred Securities"), received from [Name of Transferor] (the "Transferor") on [Date of Transfer] pursuant to Section 3([●]) of that certain Lock-Up Letter, dated [●], 2026 (the "Original Lock-Up Letter"), executed by the Transferor in favor of Westbridge Securities LLC, as Representative of the several Underwriters (the "Representative"), in connection with the initial public offering of ADSs of the Company.
In consideration of the transfer of the Transferred Securities to the undersigned, and as a condition to such transfer, the undersigned hereby agrees to be bound by all of the terms, conditions, restrictions, and obligations set forth in the Original Lock-Up Letter (a copy of which is attached hereto and incorporated herein by reference) with respect to the Transferred Securities, as if the undersigned were the original signatory thereto, for the remainder of the Lock-Up Period (as defined in the Original Lock-Up Letter). Without limiting the generality of the foregoing, the undersigned agrees as follows:
1.  During the remainder of the Lock-Up Period, the undersigned will not, without the prior written consent of the Representative, directly or indirectly: (a) offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale of, or otherwise transfer or dispose of any of the Transferred Securities, or any interest therein; (b) enter into any swap, hedge, or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership of any of the Transferred Securities, whether any such transaction is to be settled by delivery of ordinary shares, ADSs, or other securities, in cash, or otherwise; (c) make any demand for, or exercise any right with respect to, the registration of any of the Transferred Securities under the Securities Act of 1933, as amended, or under any securities laws of any other jurisdiction; (d) deposit any ordinary shares into any depositary receipt facility during the Lock-Up Period; or (e) publicly disclose the intention to do any of the foregoing.
2.  The undersigned is entitled to the same permitted exceptions set forth in Section 3 of the Original Lock-Up Letter, subject to the same conditions (including the requirement that any subsequent permitted transferee execute and deliver a lock-up letter in the form of this letter).
3.  The undersigned represents and warrants that (a) the undersigned has full power and authority to execute and deliver this letter and to perform its obligations hereunder, (b) this letter has been duly executed and delivered and constitutes a valid and binding obligation of the undersigned, enforceable in accordance with its terms, and (c) the execution, delivery, and performance of this letter will not conflict with or violate any law, regulation, order, or agreement binding upon the undersigned.
4.  The undersigned acknowledges and agrees that the Representative and each of the Underwriters would be irreparably harmed by any breach of this letter and that the Representative and the Underwriters shall be entitled to seek specific performance, injunctive relief, or other equitable remedies without the necessity of proving actual damages or posting any bond, in addition to any other remedies available at law or in equity.
5.  This letter shall be governed by and construed in accordance with the laws of the State of New York, without regard to its conflict-of-laws principles. The undersigned irrevocably submits to the exclusive jurisdiction of the federal and state courts located in the Borough of Manhattan, City of New York, New York, for any suit, action, or proceeding arising out of or relating to this letter, and irrevocably waives any objection to venue in such courts and any claim of inconvenient forum.
6.  WAIVER OF JURY TRIAL. THE UNDERSIGNED HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES, TO THE FULLEST EXTENT PERMITTED BY APPLICABLE LAW, ANY AND ALL RIGHT TO TRIAL BY JURY IN ANY SUIT, ACTION, OR PROCEEDING ARISING OUT OF OR RELATING TO THIS LETTER.
This letter shall terminate upon the expiration of the Lock-Up Period or upon the earlier termination of the Original Lock-Up Letter in accordance with Section 10 thereof.
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Very truly yours,
[NAME OF PERMITTED TRANSFEREE]
By: ________
Name:
Title:
Address:
Acknowledged:
WESTBRIDGE SECURITIES LLC, as Representative of the several Underwriters
By: ________
Name: Jonathan Hartwell
Title: Managing Director, Global Equity Capital Markets
Attachment: Copy of Original Lock-Up Letter dated [●], 2026
Type of Security | Number of Securities | Record Holder / Registered Name | Manner of Holding
Ordinary Shares (Stammaktien) — Pre-Offering | 47,945,000 | Rheintal Industrieholding GmbH | Direct (registered in share register of the Company)
Ordinary Shares to be sold in Offering (as ADSs) | (8,500,000) / 4,250,000 ADSs | Rheintal Industrieholding GmbH (to be deposited with Meridian Trust Company, N.A.) | N/A — to be transferred in Offering
Retained Shares (Lock-Up Securities) | 39,445,000 Ordinary Shares | Rheintal Industrieholding GmbH | Direct
Options / Warrants / Convertible Securities | None | N/A | N/A
Type of Security | Number of Securities | Record Holder / Registered Name | Manner of Holding
Ordinary Shares (Stammaktien) — Pre-Offering | 20,855,000 | Kestrel Capital Partners AG | Direct (registered in share register of the Company)
Ordinary Shares to be sold in Offering (as ADSs) | (4,300,000) / 2,150,000 ADSs | Kestrel Capital Partners AG (to be deposited with Meridian Trust Company, N.A.) | N/A — to be transferred in Offering
Retained Shares (Lock-Up Securities) | 16,555,000 Ordinary Shares | Kestrel Capital Partners AG | Direct
Options / Warrants / Convertible Securities | None | N/A | N/A

CONFIDENTIAL — DRAFT FOR DISCUSSION PURPOSES ONLY

FORM OF SELLING SHAREHOLDER LOCK-UP LETTER

SIGNATURE PAGE TO LOCK-UP LETTER

RHEINTAL INDUSTRIEHOLDING GESELLSCHAFT MIT BESCHRÄNKTER HAFTUNG

KESTREL CAPITAL PARTNERS AKTIENGESELLSCHAFT

ACKNOWLEDGED AND AGREED

SCHEDULE A

LOCK-UP SECURITIES

EXHIBIT A

FORM OF TRANSFEREE LOCK-UP LETTER

Record

Parties

Dates

Amounts