Market Extra: GameStop short squeeze fuels new stock-market services tracking Reddit messages

Day traders are credited with sparking a revolution on Wall Street, helping to juice the shares of GameStop Corp., and AMC Entertainment Holdings and rattling the foundation of hedge-fund investors in the process.

Day traders are credited with sparking a revolution on Wall Street, helping to juice the shares of GameStop Corp., and AMC Entertainment Holdings and rattling the foundation of hedge-fund investors in the process.