Robinhood denies claims that it sold GameStop shares out from under its traders
This is nothing new.   I had a Shearson account back in the early 1980s and bought an oil company stock that was undervalued.    One of those leveraged buyouts occurred when I was on a short vacation, and I did not find about the expiration of a buyout offer (no broker bothered to call me).   Later I found out that Shearson had sold a lot of shares from their customer accounts to get the benefit of the buyout offer, and replaced them with lower priced shares after the offer expired.   Later, Sandy W., the head of Shearson was hailed as a financial genius.   This was nearly 40 years ago.