2323 CMC Magnetics: Announcement of the company's acquisition of marketable securities

Reporting Date: 2026/05/16 Announcement Date: 2026/05/15 Announcement Time: 17:50:07 Company Code: 2323 Company Name: CMC Magnetics Subject: Announcement of the Company's Acquisition of Marketable Securities Compliance Clause: Article 20 Date of Occurrence: 2026/05/15

Explanation: 1. Securities Name: Nanya Technology Common Stock 2. Transaction Date: 2026/05/15 ~ 2026/05/15 3. Date of Board of Directors' Resolution: Not applicable 4. Other Approval Dates: Approval level: Chairman's approval, May 15, 2026 (Republic of China calendar year 115) 5. Transaction Volume, Unit Price, and Total Transaction Amount: Transaction Volume (in thousands of shares): 1,300 Unit Price (NTD): 320.21 Total Transaction Amount (NTD): 416,267,110 6. Disposal Gain (or Loss) (not applicable for acquisition of marketable securities): Not applicable 7. Relationship with the Transacted Company: None 8. As of now, the cumulative holding of these securities (including this transaction) in terms of quantity, amount, shareholding ratio, and any restrictions (e.e. pledge situations): Remaining holdings: 3,393,000 shares, Amount: NT$860,413,507, Shareholding Ratio: 0.098%, Restrictions: None 9. As of now, the proportion of investment in marketable securities (including this transaction) as listed in Article 3 of the "Regulations Governing the Acquisition or Disposal of Assets by Public Companies" to the total assets and equity attributable to owners of the parent in the company's most recent financial report, and the amount of working capital in the most recent financial report: Proportion of Total Assets: 78.53% Proportion of Equity Attributable to Owners of the Parent: 112.78% Working Capital Amount: NT$8,285,327 thousand 10. Specific purpose of acquisition or disposal: Investment portfolio 11. Opinions of dissenting directors on this transaction: None 12. Is this transaction a related party transaction: No 13. Counterparty of the transaction and its relationship with the company: Not applicable 14. Date of approval by supervisors or audit committee: Not applicable 15. Date of previous material information release on the same matter: Not applicable 16. Other matters to be explained: The authorized trader was authorized on March 31, 2026 (Republic of China calendar year 115) to conduct marketable securities transactions in the centralized trading market during the second quarter of 2026.