William Mack

William B. Mack is a shareholder and co-chair of the Financial Regulatory and Compliance Practice at Greenberg Traurig. He is experienced in advising registrants on regulatory and compliance matters relating to the SEC regulations, the Exchange Act and FINRA rules.

William’s practice involves all aspects of broker-dealer regulation, including SRO membership, supervision, employment, research, soft dollar arrangements, chaperoning, social media, use of foreign finders, anti-money laundering rules, alternative trading systems, exchanges, and market making issues. William assists broker-dealers and their associated persons to respond to regulatory examinations and enforcement proceedings with the SEC, FINRA, NYSE, and state regulatory authorities.

William assists firms in obtaining guidance, interpretive letters, and no-action relief from regulators with respect to novel securities issues and the creation of new products and services. William also advises clients on cryptocurrency, tokenization, NFTs, DeFi structures, and digital asset exchanges and trading.

Prior to joining the firm, William was a Principal Counsel for Enforcement at FINRA. Before FINRA, he was the Director of the Executive Secretariat in the Office of the U.S. Trade Representative and a Deputy Associate Counsel at the White House. William clerked for Judge Robert L. Carter (SDNY). William received his JD from Columbia Law School and his BA from SUNY Albany.