“Steffen is excellent. He knows the rules and regulations extremely well, provides sound counsel and always takes a very practical approach to issues.”
Chambers USA


Steffen Hemmerich is a partner in the New York office of Mayer Brown, Co-Head of the firm’s Financial Markets Regulatory & Enforcement practice and Head of the firm’s Broker-Dealer Regulatory & Compliance practice. He provides broker-dealer regulatory and transactional advice to domestic and foreign investment banks, financial institutions, insurance companies, investment advisers, hedge funds and private equity funds.

Steffen regularly counsels clients on federal and state broker-dealer regulatory matters and applicable self-regulatory organization (“SRO”) matters; US Securities and Exchange Commission (“SEC”) financial responsibility rules, including SEC Rule 15c3-1, as well as SEC Rule 15c3-3 and custody issues arising thereunder; custody arrangements with domestic and foreign custodians, including the negotiation of custody agreements; broker-dealer registration/formation, including structural advice, and SRO membership (FINRA, exchanges and clearing agencies); successor registration; material changes in business operations/business expansions; merger/acquisition/restructuring transactions; business transfers/consolidations; joint ventures; registration and qualification of personnel (state/SRO); foreign broker-dealer/cross-border issues under SEC Rule 15a-6 and “chaperoning” arrangements thereunder; broker-dealer “status” questions; books and records requirements; regulatory reporting and disclosure obligations; vendor/outsourcing relationships; compliance and operational systems/technologies; product development; FINRA advertising issues; digital platforms, including mobile trading apps, and digital engagement practices, including the use of predictive data analytics/artificial intelligence by broker-dealers; SEC risk assessment requirements (Form 17-H filings); and Bank Secrecy Act/Anti-Money Laundering and Office of Foreign Assets Control compliance.

Steffen also advises financial services firms and fintech companies on securities and broker-dealer regulatory matters relating to digital assets and blockchain technology, including business expansion and broker-dealer registration and custody issues.

Steffen is ranked as a leading lawyer by Chambers USA 2023 for Financial Services: Broker Dealer (Compliance). Steffen has been described as “efficient and effective… particularly vis-à-vis FINRA rules and processes.” (Chambers USA 2023).


Benjamin N. Cardozo School of Law, LLM

Goethe-University Frankfurt am Main, Germany, JD

Harvard Business School, Program for Leadership Development


  • Germany
  • New York


  • Member, American Bar Association, Section of Business Law
  • Member, American Council on Germany