The tremendous volatility on the few companies that were "shorted" by large hedge funds has forced stock trading apps to act. Yesterday TR Ameritrade, and today Robin Hood introduced restrictions on trading in shares such as GameStop or AMC, indicating that currently investors cannot buy these shares, but only sell those they own. Gamestop shares are trading under pressure in the premarket, although earlier stock surged to nearly $500 level. Currently, stock is trading around $ 290 per share (20% below yesterday closing price).
GameStop (GME.US), M30 interval. Source: xStation5