GameStop shares closed up 19 percent Thursday, after surging as much as 88 percent, as retail investors returned to the shorted stock that set off a trading frenzy last month that shocked Wall Street and sparked federal scrutiny, the Washington Post reported. GameStop ended the session at $109.15, pushing the video game retailer’s market cap past $7.6 billion, even as the broader market slumped. The Dow Jones industrial average fell 559.85 points, nearly 1.8 percent, to 31,402.01. The S&P 500 shed 96.09 points, or nearly 2.5 percent, to close at 3,829.34, while the tech-heavy Nasdaq tumbled 478.53 points, or 3.5 percent, to end at 13,119.43. Other shorted stocks that have attracted intense interest, propelled by online investor communities such as the subreddit WallStreetBets, also had big swings. Koss Corp. jumped 17 percent, to $21.53 per share, after soaring as much as 48 percent. AMC Entertainment soared 5 percent before reversing course; it closed at $8.29, down 8.8 percent.
