ANDREW SIOSON advises clients on a broad range of regulatory, compliance, enforcement and transactional matters. In this capacity, he has represented clients before the U.S. Securities and Exchange Commission (SEC), Financial Industry Regulatory Authority (FINRA), Federal Reserve Board (FRB), Public Company Accounting Oversight Board (PCAOB), and various other state and federal regulators. Andrew’s practice also focuses on issues related to cryptocurrency, tokenized assets and blockchain/distributed ledger technology. He is a member of Sidley’s global Securities Enforcement and Regulatory practice, which was named a “Compliance Practice Group of the Year” for 2023 by Law360, was named the “Law Firm of the Year” for Securities Regulation in 2024, 2020 and 2017 by U.S. News – Best Lawyers and received the 2019 Chambers USA award for Financial Services Regulation.
Prior to joining Sidley, Andrew served as special counsel at the SEC in the Division of Trading and Markets. He gained particular experience in supervision of equities and options exchanges, alternative trading systems, broker-dealers and other major securities market participants. Among many issues, Andrew worked on an SEC rulemaking related to order handling disclosures, market structure reform, FINRA and other SRO rule changes, market data and NMS plan governance, ETF listing standards and issues related to Dodd-Frank Act implementation. During his time at the SEC, Andrew received a Director’s Award for work related to security-based swaps. Before joining the SEC, he gained experience as a corporate lawyer at a firm in New York, practicing primarily in private funds, finance and mergers and acquisitions.
Andrew is a registered CPA and has held a Series 7 license.