Hedge fund D1 Capital Partners, run by billionaire Dan Sundheim, is continuing to ramp up its private market bets — having invested in at least 24 private companies in 2021 so far. The $21 billion hedge fund has been making private investments in startups since its launch in 2018. Popular among fellow Tiger Cub firms Tiger Global and Coatue Management, private investing continues to take the hedge fund world by storm this year.