This is from Wikipedia In January 2021, a short squeeze of the...

This is from Wikipedia

In January 2021, a short squeeze of the stock of the American video game retailer GameStop and other securities took place, causing major financial consequences for certain hedge funds and large losses for short sellers. Approximately 140 percent of GameStop's public float had been sold short, and the rush to buy shares to cover those positions as the price rose caused it to rise even further. The short squeeze was initially and primarily triggered by users of the subreddit r/wallstreetbets, an Internet forum on the social news website Reddit, although a number of hedge funds also participated. At its height, on January 28, the short squeeze caused the retailer's stock price to reach a pre-market value of over US$500 per share ($125 split-adjusted), nearly 30 times the $17.25 valuation at the beginning of the month. The price of many other heavily shorted securities and cryptocurrencies also increased.

There is a movie called Dumb Money about this rout as well.