Deckoff is the founder of Black Diamond Capital Management, an investment firm with $9 billion under management and offices in Stamford, Conn., London, Mumbai and St. Thomas in the U.S. Virgin Islands. Prior to launching Black Diamond in 1995, Deckoff worked his way up at different firms, becoming senior vice president of Kidder, Peabody & Co. A resident of the U.S. Virgin Islands, Deckoff donates to various community organizations in the territory. He also owns multi-million dollar properties in Colorado and New York City, and a Beverly Hills mansion previously owned by the Latsis shipping family. An affiliated entity of Black Diamond is listed as a beneficiary of a lucrative tax incentive that is intended to spur economic development in the U.S. Virgin Islands. The tax incentive has been granted to dozens of businesses with operations in the territory. Forbes estimated his net worth at $3.2 billion in February 2024.