Money SEC warns of ‘extreme market volatility,’ will review activity as GameStop stock, Robinhood drama continues January 29, 2021Nathan Bomey, USA TODAYComments Off on SEC warns of ‘extreme market volatility,’ will review activity as GameStop stock, Robinhood drama continues U.S. regulators warned Friday of "extreme stock price volatility" and will review questionable actions amid a fight over GameStop and Robinhood.