[CTBC] Announcement of Acquisition of Securities

1. Securities Name: Phison Common Stock 2. Transaction Date: June 4, 2026 ~ June 10, 2026 3. Board of Directors Approval Date: N/A 4. Other Approval Dates: Approval Level: Chairman Approval June 10, 2026 5. Transaction Quantity, Unit Price, and Total Transaction Amount: Transaction Quantity (thousands of shares): 140 Unit Price (NT$): 2,411.75 Total Transaction Amount (NT$): 337,644,684 6. Disposal Gain (or Loss) (Not applicable for acquisition of securities): N/A 7. Relationship with the Company of the Traded Securities: None 8. Accumulated Holding Quantity, Amount, Shareholding Ratio, and Circumstances of Rights Restriction (e.g., pledge) of this Transaction's Securities (including this transaction) up to the present: Balance Held: 338,000 shares, Amount: 862,269,568 NT$ Shareholding Ratio: 0.15%, Circumstances of Rights Restriction: None 9. Up to the present, the proportion of securities investments (including this transaction) listed in Article 3 of the "Rules Governing the Acquisition or Disposal of Assets by Publicly Issued Companies" to the total assets and the equity attributable to owners of the parent company in the most recent financial statements, and the amount of working capital in the most recent financial statements: Proportion of Total Assets: 81.33% Proportion of Equity Attributable to Owners of the Parent Company: 116.81% Amount of Working Capital: 8,285,327 thousand NT$ 10. Specific Purpose of Acquisition or Disposal: Investment Portfolio 11. Opinions of Directors Who Expressed Dissent Regarding This Transaction: None 12. Is This Transaction a Related Party Transaction: No 13. Counterparty to the Transaction and Relationship with the Company: N/A 14. Date of Supervisor's Approval or Audit Committee's Consent: N/A 15. Date of Previous Announcement of Major Information on the Same Event: N/A 16. Other Explanatory Matters: On March 31, 2026, authorized traders were granted the authority to conduct securities transactions in the centralized trading market during the second quarter of 2026. Keywords: Major Information