2323 CMC Magnetics: Supplemental Announcement on Securities Acquisition

1. Security name: Win Semiconductors common stock. 2. Transaction date: 2026/05/15 - 2026/05/26. 3. Board approval: N/A. 4. Authorization: Chairman (2026/05/26). 5. Quantity, unit price, total amount: 751,000 shares, NT$475.35 per share, total NT$356,989,197. 6. Disposal gain: N/A. 7. Relationship: None. 8. Current holdings: 20,000 shares, NT$9,923,056, 0.005% stake. 9. Asset ratios: 74.39% of total assets, 106.84% of equity. 10. Purpose: Investment portfolio. 11. Dissenting opinions: None. 12. Related party transaction: No. 13. Counterparty relationship: N/A. 14. Audit committee: N/A. 15. Previous announcement: 2026/05/26. 16. Other: Authorized on 2026/03/31 for Q2 trading.