Co-founded by Dan Gilbert and Josh Luber, StockX's investors include Google Ventures, Battery Ventures, Karlie Kloss and Steve Aoki. : Co-founded by Dan Gilbert and Josh Luber, StockX's investors include Google Ventures, Battery Ventures, Karlie Kloss and Steve Aoki. The company is up to 370 employees and is handling $2 million a day in transactions. It launched just over two years ago. JC Reindl/Detroit Free Press Calais Sewell, 27, of Detroit prepares authenticated goods for shipping at the new Stock X operations center.