Group 1 - Trinseo PLC is under investigation for potential securities fraud and unlawful business practices involving its officers and directors [1] - On October 6, 2025, Trinseo announced the indefinite suspension of its quarterly dividend and the permanent closure of its methyl methacrylate production operations in Rho, Italy, as well as its acetone cyanohydrin production operations in Porto Marghera, Italy [1] - The company's actions are aimed at optimizing operations, enhancing cash flow generation, and strengthening long-term profitability [1] - Following the announcement, Trinseo's stock price dropped by $0.29 per share, or 12.21%, closing at $2.05 per share on October 7, 2025 [1]