Short squeeze resulting in market calls (deposit money or forced to settle the short by buying stock)
The ones who did heavy naked selling (selling stock they don't own by contracts) all get calls from the bank with 2 options. Deposit money to cover the virtual loss, or get out of the market by buying stock/loing options at the current price
Another GameStop? Here Are the Next 10 Most Shorted Small-Caps.
https://www.barrons.com/articles/another-gamestop-here-are-the-next-10-most-shorted-small-caps-51611688092?siteid=yhoof2