Mark O’Hare became a billionaire after BlackRock acquired his data company. Now he’s turning his employees into millionaires.

“BlackRock is known for excellence in both investment management and financial technology, and together we can accelerate our efforts to deliver better private markets data and analytics to all of our clients at scale,” O’Hare said in the press release. “I look forward to joining BlackRock and continuing to play a role in the continued growth and success of Preqin and our customers.”

This is O’Hare’s second major sale after Reuters purchased his equity owner database, Citywatch, in 1998.