Justin Mateen is a serial seed investor: He’s backed over 120 startups, including the fintech Brex, which announced in January that it reached decacorn status at a $12.3 billion valuation. He is, perhaps, best known as the cofounder of Tinder (although he stepped down as the chief marketing officer of Tinder in 2014). But before he helped build the world’s most popular online dating app, Mateen was already an angel investor, using his own money to back promising startups. In 2009, while Mateen was working on a social network for celebrities, he placed an early bet on the ride-hailing company Lyft. It went public at a valuation of $24 billion a decade later. Recently he backed Deel which landed a $5.5 billion valuation in 2021. And his investing firm, Jam Fund, raised about $300 million from investors for its second fund last year.