CMC Magnetics (2323) Announces Disposal of WIN Semiconductors Shares

Announcement Date: May 21, 2026 Declaration Date: May 20, 2026 Time: 17:43:30 Company Code: 2323 Company Name: CMC Magnetics Subject: Announcement regarding disposal of marketable securities by the Company Clause: No. 20 Fact Occurrence Date: May 20, 2026

Explanation: 1. Name of Securities: WIN Semiconductors common stock 2. Transaction Date: May 11, 2026 – May 20, 2026 3. Date of Board Approval: Not applicable 4. Other Resolution Date: Chairperson authorization 5. Transaction Quantity, Unit Price, and Total Amount: Quantity (1,000 shares): 710 Unit Price (TWD): 486.21 Total Amount (TWD): 345,207,576 6. Profit/Loss on Disposal: Disposal loss of 2,543,631 TWD 7. Relationship with Target Company: None 8. Current Cumulative Holdings: Balance: 649,000 shares, Amount: 322,003,172 TWD Ownership Percentage: 0.15% 9. Ratios to Assets/Equity: Ratio to Total Assets: 79.42% Ratio to Equity Attributable to Parent Owners: 114.06% Working Capital: 8,285,327 thousand TWD 10. Purpose: Investment portfolio adjustment 11. Objection by Directors: None 12. Related Party Transaction: No 13. Relationship with Counterparty: Not applicable 14. Date of Approval by Audit Committee/Supervisor: Not applicable 15. Date of Previous Announcement: Not applicable 16. Other Remarks: Authorized traders were approved on March 31, 2026, to conduct securities trading in the centralized market during the second quarter of 2026.