Publications Memos Go Back Revised HSR Act Thresholds 01.29.08 Related Insights 12.23.25 | Publications The New York LLC Transparency Act Will Become Effective on January 1, 2026, With a Limited Scope 12.15.25 | Publications Simpson Thacher Sustainability and ESG: Regulatory Update – December 2025 12.10.25 | Publications CARB Issues Proposed Regulations Implementing SB 253 and SB 261 Related Services Related Practice Areas Corporate Litigation Mergers and Acquisitions Antitrust and Trade Regulation Complex Commercial Litigation