[CMC Magnetics] Announcement on the Disposal of Marketable Securities

1. Name of the securities: WIN Semiconductors Common Stock 2. Transaction date: 2026/5/11 ~ 2026/5/20 3. Date of board of directors' approval: Not applicable 4. Other approval date: Approval level: Chairman's approval, May 20, 2026 (ROC Year 115) 5. Transaction volume, price per unit, and total transaction amount: Transaction volume (thousand shares): 710, Price per unit (NT$): 486.21, Total transaction amount (NT$): 345,207,576 6. Disposal profit (or loss): Disposal loss of NT$2,543,631 7. Relationship with the counterparty company: None 8. To date, the cumulative quantity, amount, shareholding ratio, and any restricted rights (e.g., pledges) of this security held (including this transaction): Remaining balance: 649,000 shares, Amount: NT$322,003,172, Shareholding ratio: 0.15%, Restricted rights: None 9. To date, the ratio of securities investments (including this transaction) under Article 3 of the "Regulations Governing the Acquisition and Disposal of Assets by Public Companies" to the total assets and equity attributable to owners of the parent in the most recent financial statements, and the amount of working capital in the most recent financial statements: Ratio to total assets: 79.42%, Ratio to equity attributable to owners of the parent: 114.06%, Working capital amount: NT$8,285,327 thousand 10. Specific purpose of the acquisition or disposal: Investment portfolio 11. Opinions of directors expressing dissent to this transaction: None 12. Is this transaction a related-party transaction: No 13. Counterparty and its relationship with the company: Not applicable 14. Date of supervisors' acknowledgment or audit committee's consent: Not applicable 15. Date of previous material information announcement on the same event: Not applicable 16. Other explanatory matters: Authorization was granted on March 31, 2026 (ROC Year 115) to authorized traders to conduct securities transactions on the centralized exchange market during the second quarter of 2026.