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

• Preqin employees are getting paid after BlackRock acquired the company for $3.2 billion.
• Staffers will share about $650 million, making some of them millionaires.
• Preqin founder Mark O'Hare and his wife will walk away with about $2 billion after taxes.

Some Preqin employees are poised for a big payday after BlackRock acquired the data company for $3.2 billion.

The acquisition, announced on June 30, has made Preqin founder Mark O'Hare and his wife billionaires.

O'Hare owns nearly 80% of Preqin through Valhalla Venture and will gain about $2.6 billion from the acquisition, Fortune reported. The number shrinks to about $2 billion after taxes.

The remaining wealth, about $653 million, will be shared among Preqin management and its 1,500 employees — making some of them millionaires.

Preqin is a financial data and analytics provider focused on alternative investments. O'Hare founded the company in 2002. In a press release, Preqin said it had 30,000 private market investors, 60,000 fund managers, and 190,000 funds. The company expects to generate about $240 million in revenue in 2024.

The acquisition has deepened O'Hare's pockets enough for him to surpass BlackRock CEO Larry Fink, whose net worth is $1.7 billion. As part of the acquisition, O'Hare will also join BlackRock as a vice chair.

"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.