[CMC] Announcement regarding the acquisition of securities

1. Name of security: OptiWorks common stock 2. Transaction date: 115/5/8~115/5/27 3. Board approval date: N/A 4. Other approval date: Chairman approval, May 27, 115 5. Quantity, unit price, and total amount: 158,000 shares, NT$2,794.30 per share, total NT$441,499,894 6. Gain/Loss on disposal: N/A 7. Relationship with the target company: None 8. Cumulative holdings: 45,000 shares, NT$136,288,459, 0.05% stake, no restrictions 9. Investment ratio under asset regulations: 78.28% of total assets, 112.43% of equity attributable to owners of the parent, working capital NT$8,285,327,000 10. Purpose: Investment portfolio 11. Dissenting opinions: None 12. Related party transaction: No 13. Counterparty relationship: N/A 14. Audit committee approval: N/A 15. Previous disclosure: N/A 16. Other: Authorized on 115/03/31 for trading in Q2