Taiwan Styrene Monomer Corporation Announces Financial Information Due to Trading Alert on Securities Exchange

1. Date of Event: July 31, 115 (2026) 2. Reason for Announcement: In accordance with instructions from the Taiwan Stock Exchange Corporation 3. Financial and Operational Information:

Period Monthly Quarterly Last Four Quarters Cumulative =============== =================== =================== ============================= Most Recent Month Most Recent Quarter 114 Q2 to 115 Q1 Item Jun-115 (Consolidated Self-compiled) Q1-115 (Reviewed) (Audited/Reviewed) =============== =================== =================== ============================= Revenue 5,695 million -24.85% YoY 21,840 million -4.75% YoY 85,647.1 million Pretax Net Loss -1,578 million +931.57% YoY -4,650 million -114.74% YoY -10,125.0 million Net Loss Attributable to Owners of Parent -2,041 million +322.57% YoY -4,950 million -176.23% YoY -10,410.4 million EPS (NT$) -0.38 +322.22% YoY -0.94 -176.47% YoY -1.97

4. Whether there are material events under Article 4 of the 'Procedures for Verification and Disclosure of Material Information by Listed Companies' of the Taiwan Stock Exchange Corporation: No

5. Whether there is a need to hold a press conference under Article 11 of the above procedures: No

6. Complete financial information is available on the Public Information Observation System via the following paths: (1) Recent revenue and profit/loss: Basic Information > Highlights (2) Historical monthly revenue: Operations Overview > Monthly Revenue > Monthly Revenue Information under IFRS (3) Historical profit/loss (audited/reviewed): Financial Statements > Under IFRS > Consolidated/Individual > Comprehensive Income Statement (4) Historical profit/loss (voluntary self-compiled announcements): Operations Overview > Self-Compiled Earnings Announcements

7. Other Matters to be Disclosed: None