About 2.1 million GameStop shares failed-to-deliver on Jan. 26 before falling to 138,179 on Jan. 29, the day after Robinhood and other brokerages began restricting trading in so-called meme stocks.
https://www.reddit.com/r/wallstreetbets/comments/llxbg0/about_21_million_gamestop_shares_failedtodeliver/