HG Semiconductor Limited — AGM Information 2026

May 7, 2026

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HG SEMICONDUCTOR LIMITED

宏光半導體有限公司

(Incorporated in the Cayman Islands with limited liability)

(Stock Code: 6908)

SUPPLEMENTAL ANNOUNCEMENT TO THE AGM CIRCULAR IN RELATION TO THE RE-APPOINTMENT OF AUDITORS

Reference is made to the circular of HG Semiconductor Limited (the "Company") dated 30 April 2026 (the "AGM Circular"). Capitalised terms used herein shall have the same meanings as those defined in the Circular unless the context requires otherwise.

The board (the "Board") of directors (the "Directors") of the Company would like to provide to the shareholders of the Company with the following additional information on the re-appointment of auditors, details of which are set out in the paragraphs headed "RE-APPOINTMENT OF AUDITORS" in the section headed "LETTER FROM THE BOARD" in the AGM Circular.

RE-APPOINTMENT OF AUDITORS

Rongcheng (Hong Kong) CPA Limited ("Rongcheng") will retire as the auditors of the Company (the "Auditors") at the 2026 AGM and, being eligible, offer itself for re-appointment. Upon the recommendation of the Audit Committee, the Board proposes an ordinary resolution to be considered and, if thought fit, passed at the 2026 AGM for the re-appointment of Rongcheng as the Auditors to hold office from the conclusion of the 2026 AGM until the next annual general meeting of the Company and for authorising the Board to fix the remuneration of the Auditors for the year ending 31 December 2026.

The estimated audit fee payable to Rongcheng for the audit of the consolidated financial statements of the Company and its subsidiaries for the financial year ending 31 December 2026 is expected to be approximately RMB600,000 to RMB700,000 (exclusive of out-of-pocket expenses). Such estimated fee has been determined after due consideration and arm's length negotiations between the Company and Rongcheng, taking into account, among other things, the historical audit fees, the prevailing market rates, the complexity and business plans of the Group, the expected scope of the audit, the audit timetable, and the resources required by Rongcheng. The estimated audit fee has been determined on

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the basis that no material changes are expected in the Group's operations, accounting policies or regulatory environment during the financial year, and that the Company will provide timely and adequate assistance and information as reasonably required for the audit.

As Rongcheng is relatively familiar with the Group's financial position and affairs, the Board considers that the estimated audit fee is fair and reasonable, taking into account the facts and circumstances known as at the Latest Practicable Date, and that the audit related work in respect of the Group for the year ending 31 December 2026 will be performed more efficiently by Rongcheng, which is in the best interests of the Company and the Shareholders as a whole.

Unless there is a material change in the basis and assumptions set out above, the final audit fee should not deviate materially from the estimated amount initially disclosed. In the event of any material change, the Company will make further disclosure as appropriate.

The above supplemental information does not affect other information contained in the Circular and save as disclosed above, all other information therein remains unchanged.

By order of the Board
HG Semiconductor Limited
Dr. Xu Zhihong
Chairman and Executive Director

Hong Kong, 7 May 2026

As at the date of this announcement, the executive Directors are Dr. Xu Zhihong, Mr. Zhao Yi Wen and Mr. Li Yang; and the independent non-executive Directors are Mr. Zou Haiyan, Mr. Siu Miu Man, Simon, MH. And Ms. Liu Wanwen.

If there is any inconsistency in this announcement between the Chinese and English versions, the English version shall prevail.