S&T Announces Ex-Dividend Date and Related Matters

1. Date of Board or Shareholders' Meeting Resolution or Company Decision: 06/24/2026 2. Type of Rights or Dividend Adjustment (please enter 'Rights Issue', 'Dividend', or 'Rights and Dividend'): Dividend 3. Types and Amounts of Ordinary Share Dividends: Cash dividend to shareholders amounting to NT$941,660,490 (NT$10 per share). 4. Ex-Dividend Trading Day: 07/22/2026 5. Last Transfer Date: 07/23/2026 6. Start Date of Transfer Suspension: 07/24/2026 7. End Date of Transfer Suspension: 07/28/2026 8. Ex-Dividend Reference Date: 07/28/2026 9. Final Date for Bond Conversion Application: 07/01/2026 10. Start Date of Bond Conversion Suspension: 07/03/2026 11. End Date of Bond Conversion Suspension: 07/28/2026 12. Ordinary Share Cash Dividend Payment Date: 08/18/2026 13. Other Matters to be Disclosed: The aforementioned cash dividend amount per share is calculated based on the total outstanding shares of 94,166,049 as of the board resolution date of 03/10/2026. Should the number of outstanding ordinary shares change thereafter (e.g., due to convertible bondholders exercising conversion rights, issuance of restricted stock to employees, exercise of employee stock options, or company repurchase and transfer or cancellation of shares), resulting in changes to the shareholder dividend ratio, the Chairman is hereby authorized to make full adjustments accordingly.