Summary List PlacementRobinhood made scores of retail investors rich during the pandemic. Now as it prepares to go public, the company's S-1 filing with the SEC reveals its earliest backers are on the verge of getting much, much richer. DST Global, the late-stage firm founded by Russian-Israeli entrepreneur Yuri Milner — known for backing Facebook and Twitter — is Robinhood's biggest shareholder, owning more than 58 million shares. DST Global led Robinhood's 2018 $363 million Series D at a $5.6 billion valuation and its 2019 Series E at a $7.6 billion valuation.