Meme stocks like GameStop are hot again, reviving memories of early 2021 when they turned into a craze that ended up burning many investors along with Robinhood Markets. The online brokerage was especially popular among younger generations helped propel the meme stock boom until it became so overwhelmed that it suddenly clamped down on trading. That move outraged many customers who blamed the brokerage for losses, sparking inquiries by lawmakers and triggering lawsuits.