It turns out that these professionals needed retail investors: As professionals fled the market in February, Robinhood traders bought up stocks, acting as a market-stabilizing force, according to observers. The phenomenon was tracked by researchers Simon Glossner and Pedro Matos at the University of Virginia and Stefano Ramelli and Alexander Wagner at the University of Zurich. They looked at how institutions managed their investments during the first wave of the pandemic. By and large, allocators were “rushing to exit” the markets, Matos says. So who was buying those assets? “That led us to Ro...