Prominent hedge fund manager Bill Ackman is betting that the coronavirus pandemic could rattle the U.S. stock market again like in March in a time when major stock indexes just soared to an all-time high. Last time he made similar bets, he won and profited $2.6 billion, or a 10,000 percent return, on his investments in less than a month. Subscribe to Observer’s Daily NewsletterInterestingly, it was the same day Pfizer declared early success with its experimental COVID-19 vaccine, which sent stock indexes to a record high. However, Ackman is concerned that the news will encourage people to become nonchalant about preventive measures and actually make the pandemic worse before the vaccine gets to the market. “I hope we lose money on this next hedge,” Ackman said during a keynote speech at the event, per Financial Times.