Drew Angerer/Getty Images Martin Shkreli is betting against Opendoor stock. Once convicted of securities fraud, Shkreli now focuses primarily on stock trading. He shared a short position in Opendoor on X this week, drawing the ire of bullish retail investors. Martin Shkreli has returned. First rising to fame as the "pharma bro" who jacked up the price of an AIDS drug by 5,000% overnight and was eventually convicted of securities fraud, Shkreli is in the spotlight this week for taking aim at a stoc ...