Contract analysis

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

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

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 C

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 req

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 t

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 th

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 Cap

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. Dalmqvis

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

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 iss

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

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): • Si

1. Cover Page — Offering size (number of ADSs), ADS price range, estimated gross proceeds, underwriting discounts and commissions.

2. Prospectus Summary — Selected financial highlights for FY2023, FY2024, and FY2025; key operational and financial metrics; offering statistics.

3. Selected Consolidated Financial Data — Comparative consolidated financial data for FY2023, FY2024, and FY2025, including income statement data, balance sheet data, cash flow data, and key ratios.

4. Capitalization — Pre- and post-IPO capitalization table, showing total debt, total shareholders' equity, total capitalization, and related adjustments for the Offering.

5. Dilution — Net tangible book value per ordinary share and per ADS before and after the Offering; dilution per ADS to new investors; dilutive effect of outstanding options and other equity awards.

6. Use of Proceeds — Dollar amounts allocated to specific uses (SiC Fab 3 expansion, R&D, revolving credit facility repayment, general corporate purposes).

7. Management's Discussion and Analysis of Financial Condition and Results of Operations — Period-over-period financial comparisons; revenue growth and margin analysis; segment-level financial data; liquidity and capital resources data; contractual obligations and commitments; critical accounting estimates.

8. Business — Industry data, operational statistics (including wafer production capacity, design wins, and customer concentration), and employee headcount (approximately 8,400 full-time equivalent employees as of the most recent practicable date).

9. Principal Shareholders — Share ownership percentages and calculations for Rheintal Industrieholding GmbH, Kestrel Capital Partners AG, the ESOT, management and Vorstand members, and the public float, on both a pre- and post-Offering basis.

10. Description of American Depositary Shares — ADS ratio (1 ADS = 2 ordinary shares), depositary fees (annual depositary service fee of $0.05 per ADS per annum), and any other financial terms of the ADR program.

11. Underwriting — Gross spread (3.50%), per-ADS underwriting discounts and commissions, syndicate economics, stabilization and overallotment option mechanics, and any additional quantitative data regarding the underwriting arrangements.

12. Pro Forma Financial Presentations — To the extent included, any pro forma financial statements or financial data giving effect to the application of net proceeds, corporate restructuring, or other adjustments.

13. Exchange Rate Information — Historical EUR/USD exchange rate data and convenience translation methodology. This listing will be refined and supplemented as the prospectus drafting progresses and specific financial data tables and statistical disclosures are finalized. [End of Annexes] Metric (€ millions, except percentages) | FY2023 (Audited) | FY2024 (Audited) | FY2025 (Unaudited) Revenue | 3,214 | 3,508 | 3,820