2323 CMC Magnetics Acquires Securities of Phison Electronics

Release Date: June 26, 2026 Statement Date: June 25, 2026 Statement Time: 17:45:53 Company Code: 2323 Company Name: CMC Magnetics Corporation Subject: Announcement of Acquisition of Marketable Securities Applicable Clause: Clause 20 Factual Date: June 25, 2026

1. Security Name: Phison Electronics – Common Stock

2. Transaction Date: June 23–25, 2026

3. Board Approval Date: Not applicable

4. Other Approval Date: Approval Level: Approved by Chairman June 25, 2026

5. Transaction Quantity, Unit Price, and Total Amount: Quantity (in thousands of shares): 135 Unit Price (NT$): 2,427.06 Total Transaction Amount (NT$): 327,652,428

6. Gain (or Loss) on Disposal (Not applicable for acquisition of securities): Not applicable

7. Relationship with the Target Company: None

8. Cumulative Holdings of the Security (including this transaction) to Date – Quantity, Amount, Ownership Percentage, and Restricted Rights (e.g., pledged): Holding Balance: 293,000 shares, Amount: NT$726,710,162 Ownership Percentage: 0.13%, Restricted Rights: None

9. Cumulative Marketable Securities Investments (including this transaction) under Article 3 of the "Regulations Governing the Acquisition or Disposition of Assets by Publicly Issued Companies" as a Percentage of Total Assets and Equity Attributable to Owners of the Parent in the Company’s Latest Financial Statements, and the Amount of Working Capital in the Latest Financial Statements: Percentage of Total Assets: 82.20% Percentage of Equity Attributable to Owners of the Parent: 118.06% Working Capital Amount: NT$8,285,327 thousand

10. Specific Purpose of Acquisition or Disposal: Portfolio investment

11. Dissenting Directors’ Opinions on this Transaction: None

12. Whether this Transaction is a Related-Party Transaction: No

13. Counterparty and Relationship with the Company: Not applicable

14. Date of Supervisor’s Approval or Audit Committee’s Consent: Not applicable

15. Previous Date of Material Information Disclosure on the Same Event: Not applicable

16. Other Explanatory Matters: On March 31, 2026, authorized traders were granted authority to conduct securities transactions on the centralized market during the second quarter of 2026.