PRIVILEGED & CONFIDENTIAL ATTORNEY WORK PRODUCT
CALDERWOOD & HARKNESS LLP One Liberty Plaza, 42nd Floor New York, NY 10006
Telephone: (212) 558-4000 Facsimile: (212) 558-3588 www.calderwoodharkness.com
Matter No. 1032-00003
[__], 2026
Graham Templeton, Esq. Partner Blackmere & Whitfield LLP 7 Times Square New York, NY 10036
Copy to:
Dieter Kaufmann Wirtschaftsprüfer, Audit Engagement Partner Blackmere & Whitfield GmbH Wirtschaftsprüfungsgesellschaft Ganghoferstraße 29 80339 Munich, Germany
Re: Request for Comfort Letters — Halcyon Semiconductor Aktiengesellschaft — Initial Public Offering of American Depositary Shares; Registration Statement on Form F-1
Dear Mr. Templeton:
1. Introduction and Background
Calderwood & Harkness LLP ("C&H" or "we") serves as United States securities counsel to Halcyon Semiconductor Aktiengesellschaft ("Halcyon" or the "Company"), a German Aktiengesellschaft incorporated and registered in Munich, Bavaria, Federal Republic of Germany (Commercial Register No. HRB 217458, Amtsgericht München), with its principal executive offices at Maximilianstraße 72, 80539 Munich, Germany. We write to you in connection with the Company's planned initial public offering (the "Offering") of American Depositary Shares ("ADSs") in the United States, as more fully described below, and to formally request that Blackmere & Whitfield LLP ("B&W" or "Blackmere & Whitfield"), together with Blackmere & Whitfield GmbH Wirtschaftsprüfungsgesellschaft ("B&W GmbH WPG" and, together with B&W, the "Firm"), issue comfort letters (collectively, the "Comfort Letters") to the underwriting syndicate and their counsel in connection with the Offering, in accordance with the standards and procedures described in this letter.
The Offering. Halcyon intends to pursue an initial public offering of ADSs in the United States through the establishment of a Level III American Depositary Receipt ("ADR") program. In connection with the Offering, the Company intends to file a Registration Statement on Form F-1 (the "Registration Statement") under the Securities Act of 1933, as amended (the "Securities Act"), with the United States Securities and Exchange Commission (the "SEC"). The Company's ordinary shares (Stammaktien) are currently listed and traded on the Frankfurt Stock Exchange (Frankfurter Wertpapierbörse) under the ticker symbol "HCY" on the Prime Standard segment of the Regulated Market (Regulierter Markt). The ADSs are expected to be listed on the Nasdaq Global Select Market under the proposed ticker symbol "HCYN."
ADS Structure. The ADSs will be issued by Meridian Trust Company, N.A. (the "Depositary"), acting as depositary under a deposit agreement to be entered into among the Company, the Depositary, and holders of ADSs. Each ADS will represent two (2) ordinary shares (Stammaktien) of the Company (the "ADS Ratio" of 1 ADS = 2 ordinary shares).
Offering Composition and Size. The Offering is expected to consist of the following:
(a) Primary ADSs: 15,000,000 ADSs (representing 30,000,000 newly issued ordinary shares to be issued from authorized capital (genehmigtes Kapital) of the Company) to be offered and sold by the Company;
(b) Secondary ADSs: 6,400,000 ADSs (representing 12,800,000 existing ordinary shares) to be offered and sold by the selling shareholders, namely Rheintal Industrieholding GmbH and Kestrel Capital Partners AG (collectively, the "Selling Shareholders"); and
(c) Overallotment Option: Up to 3,210,000 additional ADSs (representing 15% of the base deal), which may be purchased by the underwriters pursuant to an overallotment option to be granted under the Underwriting Agreement.
The total base deal offering will therefore consist of 21,400,000 ADSs (the "Base Deal"). The anticipated ADS price range is $39.00 to $45.00 per ADS, resulting in targeted gross proceeds of approximately $900,000,000 at the mid-point of the range (based on the Base Deal, excluding any exercise of the overallotment option).
Underwriting Syndicate. The Offering will be managed by the following underwriters (collectively, the "Underwriters"):
• Westbridge Securities LLC — Lead Left Bookrunner
• Pinnacle Morgan & Co., Inc. — Joint Bookrunner
• Andover Barcliffe Group Inc. — Joint Bookrunner
• Northpointe Capital LLC — Co-Manager
Westbridge Securities LLC ("Westbridge") will act as representative of the several Underwriters named in the Underwriting Agreement. Varen & Kessler LLP ("V&K") is acting as United States counsel to the Underwriters (Martin Ashford, Partner; Priya Ranganathan, Senior Associate).
Blackmere & Whitfield as Independent Auditors. Blackmere & Whitfield serves as Halcyon's independent registered public accounting firm. B&W GmbH WPG, based in Munich, serves as the Company's statutory auditor (Abschlussprüfer) under German law. B&W LLP, based in New York, is registered with the Public Company Accounting Oversight Board (the "PCAOB"). B&W has audited the Company's consolidated financial statements for the fiscal years ended December 31, 2023 and December 31, 2024, which have been prepared in accordance with International Financial Reporting Standards ("IFRS") as issued by the International Accounting Standards Board (the "IASB"). The Company's consolidated financial data for the fiscal year ended December 31, 2025 ("FY2025") is currently unaudited.
Purpose of This Letter. The purpose of this letter is to formally request that Blackmere & Whitfield issue the Comfort Letters to the Underwriters and their counsel in connection with the Offering, covering the financial and statistical information described below, and to set forth the scope, procedures, and timing that we anticipate will govern the preparation and delivery of such Comfort Letters. We recognize that the final form and content of the Comfort Letters will be subject to the circle-up process among the parties and to the professional judgment of Blackmere & Whitfield. This letter is intended to initiate that process and to provide Blackmere & Whitfield with sufficient information to commence its review and preparation.
2. Applicable Professional Standards
2.1 US Standards — SAS 72 (AU Section 634) / AS 6101
We request that the Comfort Letters be prepared in accordance with the American Institute of Certified Public Accountants ("AICPA") Statement on Auditing Standards No. 72 ("SAS 72"), codified at AU Section 634 ("Letters for Underwriters and Certain Other Requesting Parties"), as well as the corresponding standards of the Public Company Accounting Oversight Board, specifically PCAOB Auditing Standard AS 6101 ("Letters for Underwriters and Certain Other Requesting Parties"). We understand that these standards set forth the form, content, and procedures applicable to letters issued by independent accountants to underwriters in connection with securities offerings registered under the Securities Act.
The Comfort Letters should be addressed to the Underwriters — specifically, to Westbridge Securities LLC, as representative of the several Underwriters named in the Underwriting Agreement — and, with your consent, to their counsel, Varen & Kessler LLP. We note that both the Underwriting Agreement and the customary practice in offerings of this nature contemplate that the Underwriters and their counsel are the appropriate requesting and receiving parties for purposes of SAS 72 and AS 6101.
We expect that Blackmere & Whitfield LLP, through its New York office and as a firm registered with the PCAOB, will sign or co-sign the Comfort Letters. To the extent that B&W GmbH WPG in Munich also participates in the engagement, we request that the letter indicate the nature and scope of such participation, consistent with the requirements of the applicable professional standards and the Firm's global network policies.
2.2 International Standards — ISAE 3000 / ISAE 3420
To the extent that B&W GmbH WPG in Munich participates in the preparation or delivery of the Comfort Letters — whether through the performance of substantive audit or review procedures, the provision of underlying workpapers, or the issuance of a separate or supplemental comfort communication — we request that any work performed by B&W GmbH WPG also comply with the International Standard on Assurance Engagements 3000 (Revised) ("ISAE 3000"), issued by the International Auditing and Assurance Standards Board ("IAASB"), and, as applicable, ISAE 3420 ("Assurance Engagements to Report on the Compilation of Pro Forma Financial Information"). The application of ISAE 3420 may be relevant to the extent that pro forma financial information is included in the Registration Statement, as discussed further in Section 4.4 below.
We request that Blackmere & Whitfield confirm at the earliest practicable date that a dual-standard approach — combining SAS 72/AS 6101 compliance through the New York office and ISAE 3000/ISAE 3420 compliance through the Munich office — is feasible given the Firm's global network structure and internal quality control policies. If there are any limitations or qualifications that would need to be addressed in adopting this dual-standard approach, we ask that you identify them promptly so that we may consider them in the context of the overall offering timeline.
2.3 Coordination Between US and German Audit Offices
Given the cross-border nature of this engagement, we request that Graham Templeton (Partner, B&W New York) and Dieter Kaufmann (Wirtschaftsprüfer, Audit Engagement Partner, B&W GmbH WPG Munich) coordinate internally to ensure full consistency between the PCAOB/SAS 72 comfort to be delivered by the New York office and any ISAE-based assurance or supporting work to be performed by the Munich office. In particular, it is important that there be no inconsistency or gap between the procedures performed under the respective standards, the cut-off dates applied, and the representations and negative assurance provided.
We further request that a single point of contact be designated for purposes of Comfort Letter drafting, circle-up, and related communications among the working group. We understand that Graham Templeton may serve in this capacity, but we would appreciate confirmation. All communications regarding the Comfort Letters should be coordinated through this designated contact to ensure efficient and orderly progression of the circle-up process.
3. Scope of Comfort Letters Requested
3.1 Initial Comfort Letter (Delivery at Effectiveness/Pricing)
We request that Blackmere & Whitfield deliver an initial comfort letter (the "Initial Comfort Letter") on the date of execution of the Underwriting Agreement, which is anticipated to be the pricing date of the Offering. Based on the current offering timeline, the anticipated pricing date is July 1, 2026. The Initial Comfort Letter should be addressed to Westbridge Securities LLC, as representative of the several Underwriters named in the Underwriting Agreement, and should cover the financial and statistical data described in Sections 4 and 5 of this letter as of the relevant dates and for the relevant periods specified therein. The Initial Comfort Letter should be in a form that satisfies the conditions to closing set forth in the Underwriting Agreement with respect to the delivery of comfort letters.
3.2 Bring-Down Comfort Letter (Delivery at Closing)
We request that Blackmere & Whitfield deliver a bring-down comfort letter (the "Bring-Down Comfort Letter") at the closing of the Offering, which is anticipated to occur on July 6, 2026 (T+2 settlement). The Bring-Down Comfort Letter should be addressed to the same addressees as the Initial Comfort Letter and should update the Initial Comfort Letter to a date not more than two (2) business days prior to the date of the Bring-Down Comfort Letter (the "Bring-Down Cut-Off Date"). The Bring-Down Comfort Letter should confirm that, as of the Bring-Down Cut-Off Date, the conclusions and negative assurance contained in the Initial Comfort Letter remain accurate, subject to any changes, developments, or qualifications identified by Blackmere & Whitfield during the intervening period.
3.3 Additional Bring-Down Comfort Letter (If Overallotment Option Exercised)
In the event that the Underwriters exercise the overallotment option (for up to 3,210,000 additional ADSs, exercisable for a period of 30 days following the pricing date, i.e., through July 31, 2026), we request that Blackmere & Whitfield deliver an additional bring-down comfort letter (the "Overallotment Bring-Down Letter") as of the closing of the overallotment purchase. The Overallotment Bring-Down Letter should update the Bring-Down Comfort Letter to a date not more than two (2) business days prior to the date of the Overallotment Bring-Down Letter. If the overallotment option is exercised in multiple tranches, a separate Overallotment Bring-Down Letter may be required for each tranche closing. We will advise you promptly regarding the exercise of the overallotment option and any associated timing requirements.
4. Financial Data and Periods to Be Covered
4.1 Audited Financial Statements
The Registration Statement will include the Company's audited consolidated financial statements for the fiscal years ended December 31, 2023 and December 31, 2024, each prepared in accordance with IFRS as issued by the IASB, together with the related notes thereto and the independent auditors' reports of Blackmere & Whitfield thereon. We request that the Comfort Letters include a statement confirming that the audit reports on the FY2023 and FY2024 consolidated financial statements are unqualified (i.e., that they express an unmodified opinion) and that there has been no change in the independent auditor's opinion since the date on which such reports were originally issued. If there are any modifications, qualifications, or emphasis-of-matter paragraphs in the audit reports, we request that they be identified and discussed in the Comfort Letters.
4.2 Unaudited Interim / Annual Financial Data (FY2025)
The Registration Statement is also expected to include, and the prospectus will contain, the Company's unaudited consolidated financial data for the fiscal year ended December 31, 2025. As noted above, the FY2025 annual financial statements have not yet been audited by Blackmere & Whitfield, and the audit is expected to be completed during the offering process. We request that the Comfort Letters address the following key unaudited financial data points for FY2025, among others:
• Revenue: €3,820 million
• EBITDA: €1,069 million (28.0% EBITDA margin)
• Net income: €612 million
• Total assets: €7,450 million
• Total debt: €890 million
• Cash and cash equivalents: €740 million
• Net debt (total debt less cash and cash equivalents): €150 million
• Capital expenditures: €820 million
We request that Blackmere & Whitfield provide negative assurance with respect to all unaudited financial information included or incorporated by reference in the Registration Statement and prospectus, in accordance with SAS 72 and AS 6101. Specifically, we request a statement to the effect that nothing came to the attention of Blackmere & Whitfield that caused them to believe that the unaudited consolidated financial data for FY2025 as presented in the Registration Statement does not conform in all material respects with IFRS applied on a basis substantially consistent with that of the audited consolidated financial statements for FY2023 and FY2024, or that any material modifications should be made to such unaudited financial data for it to be in conformity with IFRS.
We note that to the extent the FY2025 audit is completed prior to the effectiveness of the Registration Statement, the Registration Statement may be amended to include audited FY2025 financial statements, in which case the scope of the Comfort Letters will be adjusted accordingly. We will keep you advised of any such developments.
4.3 Selected Financial Data and Statistical Information
The Comfort Letters should cover all financial data tables, selected financial data, and statistical information appearing in the prospectus, including, without limitation, the data presented in the following sections:
(a) "Prospectus Summary" (selected financial highlights);
(b) "Selected Consolidated Financial Data" (comparative financial data for FY2023, FY2024, and FY2025);
(c) "Capitalization" (pre- and post-IPO capitalization tables); and
(d) "Dilution" (dilution per ADS calculations).
In particular, the Comfort Letters should cover the following data points, which are expected to appear in the prospectus:
• Revenue compound annual growth rate ("CAGR") for FY2023 through FY2025: approximately 9.0%
• Ordinary shares outstanding immediately prior to the Offering: 215,000,000 ordinary shares, no par value (Stückaktien)
• Ordinary shares to be outstanding immediately following the Offering (assuming no exercise of the overallotment option): 245,000,000 ordinary shares (reflecting the issuance of 30,000,000 new ordinary shares underlying the 15,000,000 primary ADSs)
• Pre- and post-IPO capitalization tables, including total capitalization, total stockholders' equity, total debt, and related line items
• Dilution per ADS calculations, including net tangible book value per ADS before and after the Offering and the dilution in net tangible book value per ADS to new investors
4.4 Pro Forma Financial Information (If Applicable)
To the extent that any pro forma financial information is included in the Registration Statement — for example, giving pro forma effect to the application of approximately $100,000,000 of estimated net proceeds from the Offering to the repayment of the Company's revolving credit facility tranche — we request that such pro forma financial data be covered in the Comfort Letters. This may include pro forma adjustments to total debt, interest expense, cash and cash equivalents, and related line items. If ISAE 3420 applies to the pro forma financial information, we request that B&W GmbH WPG perform the necessary procedures under that standard in coordination with B&W LLP.
4.5 MD&A Financial Data
The Comfort Letters should cover all financial data, financial ratios, and statistical information appearing in the "Management's Discussion and Analysis of Financial Condition and Results of Operations" ("MD&A") section of the prospectus. This includes, without limitation, period-over-period changes in revenue, cost of revenue, gross profit, operating expenses, EBITDA, net income, and other financial metrics discussed in the MD&A, as well as any segment-level financial data, key performance indicators, and operational metrics referenced therein.
4.6 Non-IFRS Measures
The Registration Statement and prospectus are expected to present certain non-IFRS financial measures, including EBITDA and EBITDA margin, among others. We request that the Comfort Letters cover all non-IFRS financial measures presented in the Registration Statement, including the reconciliation tables that reconcile each such non-IFRS measure to the nearest IFRS measure. Given the SEC's heightened scrutiny of non-IFRS financial measures in registration statements, it is important that the agreed-upon procedures extend to the mathematical accuracy and internal consistency of such reconciliations.
4.7 Exchange Rate Data
The prospectus is expected to present EUR/USD exchange rate data for the convenience of US investors, including a reference exchange rate of €1.00 = $1.078 as of January 10, 2026 (based on the European Central Bank reference rate). To the extent that the prospectus includes convenience translations of financial data into US dollars — for example, presenting FY2025 revenue of approximately $4,117.96 million (€3,820 million translated at the foregoing rate) — we request that the Comfort Letters cover the mathematical accuracy of such convenience translations. We also request that the Comfort Letters confirm the source of the exchange rates used.
5. Specific Comfort Procedures Requested
5.1 Independence. We request that the Comfort Letters include a statement confirming that Blackmere & Whitfield (both B&W LLP and B&W GmbH WPG) is independent of Halcyon Semiconductor AG within the meaning of:
(a) Rule 2-01 of Regulation S-X promulgated under the Securities Act and the Securities Exchange Act of 1934, as amended;
(b) the independence standards established by the PCAOB, including PCAOB Rule 3520 and the related independence requirements; and
(c) the Wirtschaftsprüferordnung ("WPO"), the German law governing the professional responsibilities and independence of Wirtschaftsprüfer (German public auditors).
If there are any matters that could reasonably be considered to bear on B&W's independence, we request that such matters be identified and disclosed to us promptly so that they may be evaluated in the context of the applicable regulatory requirements.
5.2 Compliance of Financial Statements with SEC Requirements
We request that the Comfort Letters include a statement confirming that the audited consolidated financial statements included in the Registration Statement comply as to form in all material respects with the applicable accounting requirements of the Securities Act and the rules and regulations of the SEC thereunder, including Regulation S-X. This confirmation should specifically address the requirements applicable to foreign private issuers reporting under IFRS on Form F-1, including the requirements of Item 8 of Form 20-F (as incorporated by reference into Form F-1), and any applicable SEC Staff guidance relating to IFRS financial statements.
5.3 Negative Assurance on Unaudited Financial Information
As discussed in Section 4.2 above, we request that the Comfort Letters include negative assurance with respect to all unaudited financial information included in the Registration Statement, stating that nothing came to the attention of Blackmere & Whitfield that caused them to believe that:
(a) the unaudited consolidated financial data for FY2025 included in the Registration Statement does not conform in all material respects with IFRS as issued by the IASB applied on a basis substantially consistent with that of the audited consolidated financial statements for FY2023 and FY2024; or
(b) any material modifications should be made to such unaudited financial data for it to be in conformity with IFRS.
We understand that, under SAS 72 and AS 6101, the provision of negative assurance requires that B&W have performed a review of the unaudited financial data in accordance with applicable standards (including PCAOB AS 4105 or ISRE 2410, as applicable). If a review has not been completed as of the date of this letter, we request that B&W undertake the necessary review procedures in connection with the preparation of the Comfort Letters and advise us of the expected timing for completion.
5.4 Agreed-Upon Procedures
We request that Blackmere & Whitfield perform agreed-upon procedures in connection with the Comfort Letters, including reading and comparing specific financial and statistical data appearing in the prospectus against the Company's underlying accounting records, minutes of meetings of the Vorstand (Management Board) and Aufsichtsrat (Supervisory Board), and other supporting documents and schedules furnished by the Company. The scope of these agreed-upon procedures will include, without limitation:
(a) comparing the financial data in the prospectus to the corresponding amounts in the Company's audited consolidated financial statements and unaudited financial records;
(b) tracing specific dollar and euro amounts, percentages, and other numerical data in the prospectus to the Company's accounting records and supporting schedules;
(c) recalculating mathematical computations, including percentage changes, margins, ratios, per-share and per-ADS data, and other derived figures appearing in the prospectus; and
(d) reading the minutes of meetings of the Vorstand and Aufsichtsrat and any committees thereof held through the cut-off date, and inquiring of senior officers of the Company, to identify any matters that could be relevant to the financial information covered by the Comfort Letters.
We note that the specific scope of the agreed-upon procedures will be finalized during the circle-up process in coordination with the Underwriters and their counsel, Varen & Kessler LLP (Martin Ashford, Partner; Priya Ranganathan, Senior Associate). We will provide you with a detailed listing of specific data points and prospectus page references as the drafting of the prospectus progresses.
5.5 Subsequent Events / Change Period
We request that the Comfort Letters include a statement regarding subsequent events occurring during the "change period" — that is, the period from the date of the most recent audited or reviewed balance sheet included in the Registration Statement through a "cut-off date" not more than five (5) business days prior to the date of the Initial Comfort Letter. Specifically, we request a statement that, during the change period, there has been no change in the following specified financial line items, except as disclosed in the Registration Statement or the Comfort Letters:
(a) capital stock (Grundkapital) or total shareholders' equity;
(b) total long-term debt and short-term borrowings;
(c) net income (or net loss);
(d) total assets; and
(e) such other financial line items as may be agreed upon during the circle-up process.
In each Bring-Down Comfort Letter (including any Overallotment Bring-Down Letter), we request that the change period statement be updated through a date not more than two (2) business days prior to the date of such Bring-Down Letter.
6. Circle-Up Procedures
6.1 Initial Circle-Up
We request that Blackmere & Whitfield circulate a first draft of the Comfort Letters promptly after the circulation of the first draft of the Form F-1 Registration Statement among the working group, which is currently targeted for March 9, 2026. We understand that the first draft of the Comfort Letters may be preliminary in nature and subject to significant revision as the prospectus is developed and refined. C&H will coordinate with Varen & Kessler LLP and the Underwriters to provide consolidated comments on the draft Comfort Letters in a timely manner.
6.2 Iterative Circle-Up
We anticipate that subsequent drafts of the Comfort Letters will need to be circulated following each material amendment or revision to the Registration Statement during the offering process. Based on the current timeline, we expect the following key milestones at which updated Comfort Letter drafts should be circulated:
(a) following the all-parties drafting session (currently scheduled for March 23–24, 2026);
(b) following the confidential submission of the draft Registration Statement to the SEC (targeted for April 14, 2026);
(c) following the filing of Amendment No. 1 to the Registration Statement (targeted for May 26, 2026, in response to any SEC Staff comment letter); and
(d) following the public filing of the Registration Statement (targeted for June 8, 2026).
We recognize that additional intermediate drafts may be necessary depending on the nature and extent of SEC Staff comments and any resulting amendments to the Registration Statement. We will work with Blackmere & Whitfield and the other parties to the working group to manage the circle-up process efficiently.
6.3 Final Circle-Up Prior to Pricing
The final form of the Initial Comfort Letter should be agreed by all parties no later than the launch of the roadshow, which is currently targeted for June 23, 2026. It is essential that the form and content of the Comfort Letters be fully resolved prior to the commencement of the roadshow in order to avoid any disruption to the marketing process. Execution and delivery of the Initial Comfort Letter will occur on the pricing date (currently targeted for July 1, 2026), contemporaneously with the execution of the Underwriting Agreement.
6.4 Bring-Down Circle-Up
We request that Blackmere & Whitfield circulate a draft of the Bring-Down Comfort Letter at least two (2) business days prior to the anticipated closing date (currently targeted for July 6, 2026). The Bring-Down Comfort Letter should be in substantially the same form as the Initial Comfort Letter, updated to reflect the Bring-Down Cut-Off Date and any changes in the covered financial information during the intervening period. To the extent that any developments during the change period require modifications to the Bring-Down Comfort Letter, we ask that such modifications be communicated to the working group as promptly as practicable.
7. Addressees and Reliance
The Comfort Letters should be addressed to Westbridge Securities LLC, as representative of the several Underwriters named in the Underwriting Agreement, including:
• Pinnacle Morgan & Co., Inc.
• Andover Barcliffe Group Inc.
• Northpointe Capital LLC
The contact person at Westbridge Securities LLC for purposes of the Comfort Letters is:
Jonathan Hartwell Managing Director, Global Equity Capital Markets Westbridge Securities LLC 383 Madison Avenue New York, NY 10179
We request that Varen & Kessler LLP (Martin Ashford, Partner), as counsel to the Underwriters, also be permitted to rely on the Comfort Letters. We understand that the permissibility of such reliance is subject to Blackmere & Whitfield's professional standards and internal policies, and we ask that you confirm whether such reliance can be extended.
We note that the Company (Halcyon Semiconductor AG) and Calderwood & Harkness LLP, as counsel to the Company, are not addressees of the Comfort Letters and will not be entitled to rely thereon. However, we request that copies of all drafts and final versions of the Comfort Letters be provided to us for information purposes, in order to facilitate the overall coordination of the offering process and to enable us to advise the Company in connection with the Registration Statement and the Underwriting Agreement.
8. Coordination with Halcyon Management and German Counsel
We request that Blackmere & Whitfield coordinate with the following representatives of the Company in preparing the Comfort Letters and performing the procedures described herein:
Halcyon Semiconductor AG:
• Katarina Dalmqvist, Chief Financial Officer (Finanzvorstand and member of the Vorstand)
• Wilhelm Ostermann, General Counsel (Chefjustitiar)
Ms. Dalmqvist will serve as the principal contact within the Company for all financial data, accounting records, and supporting documentation required in connection with the Comfort Letters. The Company's finance team will make available all necessary books, records, schedules, and workpapers under Ms. Dalmqvist's direction.
In addition, to the extent that German law matters relating to auditor responsibilities, statutory audit requirements, or the duties of the Wirtschaftsprüfer arise in connection with the preparation or delivery of the Comfort Letters, the Company's German legal counsel should be consulted:
Bähr Stein Rechtsanwälte PartGmbB:
• Dr. Christoph Maurelban, Partner
• Johanna Weiß, Senior Associate
• Bockenheimer Landstraße 20, 60323 Frankfurt am Main, Germany
We anticipate that coordination with Bähr Stein may be particularly relevant with respect to matters arising under the WPO, the Handelsgesetzbuch ("HGB"), and the interaction between German statutory audit obligations and US securities law requirements.
9. Engagement Terms and Fee Arrangements
We note that the Comfort Letter engagement between Blackmere & Whitfield and the Underwriters will be subject to a separate engagement letter to be entered into between Blackmere & Whitfield and the underwriting syndicate (or its representative, Westbridge Securities LLC). The terms of such engagement letter, including the scope of services, limitations of liability, and other customary provisions, will be negotiated directly between Blackmere & Whitfield and the Underwriters (with the involvement of their counsel, Varen & Kessler LLP, as appropriate).
We request that Blackmere & Whitfield provide a draft of such engagement letter to Calderwood & Harkness LLP for review at the earliest practicable date. While we recognize that the Company is not a party to the Comfort Letter engagement, it is customary for Company counsel to review the engagement letter to ensure that its terms are consistent with the overall offering structure and the Company's obligations under the Underwriting Agreement.
Any fees and expenses for the Comfort Letter work should be communicated to both Calderwood & Harkness LLP and the Company's Chief Financial Officer, Katarina Dalmqvist, for budgeting and approval purposes. We note that the allocation of Comfort Letter fees between the Company and the Underwriters will be addressed in the Underwriting Agreement.
10. Requested Timing for Response
We request your acknowledgment of receipt of this letter and a preliminary response regarding the feasibility of the requested scope within ten (10) business days of the date hereof. In particular, we would appreciate your preliminary views on the following:
(a) the feasibility of issuing Comfort Letters under the dual-standard approach described in Section 2;
(b) any anticipated issues or limitations with respect to the scope of coverage requested in Sections 4 and 5;
(c) the anticipated staffing and resource requirements on Blackmere & Whitfield's side; and
(d) the timeline for circulation of the first draft of the Comfort Letters.
We further request your availability for a preliminary call to discuss scope, logistics, and timeline. We suggest that the following individuals participate in such call:
• Graham Templeton (Blackmere & Whitfield LLP, New York)
• Dieter Kaufmann (Blackmere & Whitfield GmbH WPG, Munich)
• Vivienne St. Claire (Calderwood & Harkness LLP, New York)
• Claire Dempsey (Calderwood & Harkness LLP, New York)
• Katarina Dalmqvist (Halcyon Semiconductor AG, Munich)
Please advise us of your availability during the next two weeks, and we will coordinate scheduling.
11. Key Financial Data Reference Table
For your reference, we set forth below a summary of the key financial data points that are expected to appear in the prospectus and will require coverage under the Comfort Letters. This table is intended to serve as a preliminary guide and is not intended to be exhaustive. The specific data points to be covered will be finalized during the circle-up process as the prospectus is developed.
Table 1: Key Consolidated Financial Data — Halcyon Semiconductor AG
Note: All financial data reflects the Company's consolidated financial statements prepared in accordance with IFRS as issued by the IASB. FY2023 and FY2024 data is derived from the audited consolidated financial statements of the Company. FY2025 data is unaudited and is subject to the completion of the year-end audit by Blackmere & Whitfield. EBITDA is a non-IFRS measure; reconciliation to net income will be presented in the prospectus.
EUR/USD Exchange Rate: For purposes of convenience translations of financial data into US dollars, the prospectus is expected to use a reference exchange rate of €1.00 = $1.078 (European Central Bank reference rate as of January 10, 2026).
12. Offering Data Points Requiring Coverage
In addition to the financial data set forth in Section 11 above, the following offering-specific data points are expected to appear in the prospectus and may require verification or coverage under the agreed-upon procedures portion of the Comfort Letters:
Table 2: Key Offering Data Points
Use of Proceeds Allocation (to the extent financial data verification is needed):
• SiC Fab 3 expansion, Dresden: approximately $280,000,000
• R&D — next-generation GaN power devices: approximately $140,000,000
• Revolving credit facility repayment: approximately $100,000,000
• General corporate purposes and working capital: approximately $87,950,000
Post-IPO Ownership (base deal, no greenshoe):
• Rheintal Industrieholding GmbH: approximately 16.1% (39,445,000 ordinary shares)
• Kestrel Capital Partners AG: approximately 6.8% (16,555,000 ordinary shares)
• Employee Share Ownership Trust ("ESOT"): approximately 3.1% (approximately 6,665,000 ordinary shares, based on the most recent trustee report)
• Public float (including ADS holders): remaining balance
We note that the post-IPO ownership percentages and share amounts set forth above are preliminary estimates based on the assumed offering composition and ADS price range and will be subject to adjustment as the offering terms are finalized.
Closing
We appreciate Blackmere & Whitfield's longstanding relationship with Halcyon Semiconductor AG and your cooperation in connection with this important transaction. We recognize that the preparation and delivery of comfort letters in the context of a cross-border initial public offering of this scale and complexity requires substantial effort and coordination among multiple offices and professional teams, and we are committed to working closely with you throughout the process to ensure a smooth and efficient circle-up.
Calderwood & Harkness LLP stands ready to discuss any aspect of this request at your convenience. Should you have any questions, or if you would like to schedule the preliminary call referenced in Section 10 above, please do not hesitate to contact the undersigned or any member of the C&H team identified below.
Vivienne St. Claire Partner, Capital Markets Calderwood & Harkness LLP One Liberty Plaza, 42nd Floor New York, NY 10006 Tel: (212) 558-4217
Email: vstclaire@calderwoodharkness.com
Claire Dempsey Lead Associate, Capital Markets Calderwood & Harkness LLP One Liberty Plaza, 42nd Floor New York, NY 10006 Tel: (212) 558-4893
Email: cdempsey@calderwoodharkness.com
We look forward to your response.
Very truly yours,
CALDERWOOD & HARKNESS LLP
By: ________
Vivienne St. Claire Partner
cc: (via email)
Katarina Dalmqvist, Chief Financial Officer (Finanzvorstand), Halcyon Semiconductor AG
Wilhelm Ostermann, General Counsel (Chefjustitiar), Halcyon Semiconductor AG
Robert Adeyemi, Billing Partner, Calderwood & Harkness LLP
Claire Dempsey, Lead Associate, Calderwood & Harkness LLP
Audrey Zhou, Working Associate, Calderwood & Harkness LLP
Martin Ashford, Partner, Varen & Kessler LLP (counsel to the Underwriters)
Jonathan Hartwell, Managing Director, Global Equity Capital Markets, Westbridge Securities LLC (Lead Left Bookrunner)
Dr. Christoph Maurelban, Partner, Bähr Stein Rechtsanwälte PartGmbB (German counsel to the Company)