Gene has tried more than a dozen federal criminal cases, and briefed and argued numerous appeals before the U.S. Court of Appeals for the Second Circuit. He has been recognized by Chambers for Litigation: White Collar Crime Government Investigations, where he is described as “a strong, zealous advocate” and is known for his “sophisticated criminal defense practice.” He is a frequent contributor to publications and speaks regularly at conferences on the subjects of digital asset, business crime and insider trading enforcement issues. 

Gene has extensive experience in handling sophisticated securities and business crime matters and has achieved notable results for clients over the course of his career. Before joining A&O, Gene was an Assistant U.S. Attorney (AUSA) for the Southern District of New York and a member of the Securities and Commodities Fraud Unit, serving as the lead attorney in numerous federal jury trials and complex white-collar investigations. 

During his tenure as an AUSA, he represented the government in the trial and conviction of former SAC Capital portfolio manager, Mathew Martoma, in the largest insider trading scheme ever charged. Gene also led the investigation in the so-called "London Whale" case concerning allegations of mismarking; and conducted the investigation that led to the conviction of former bank executives and traders for deliberately overstating the value of certain real estate backed securities. This case became one of the few successful criminal prosecutions arising out of the financial crisis. 

Gene has represented clients in actions and investigations by DOJ, various U.S. Attorney's Offices, the SEC, the CFTC, FINCEN, and FINRA, as well as other federal and state regulatory agencies.

Gene has worked on cases popularized and dramatized in popular media, including in the movie The Big Short and on the TV series Billions.