Some dude on reddit was like, yo, you wanna mess with Wall Street? So a ton of people bought stocks for companies like GameStop (the most memed company, and was actually kind of saved) and AMC so a few companies got scared people weren’t being smart, and they actually lost millions of dollars. (Not the redditors, Wall Street and some of their companies). So those companies are attempting to ban people from buying stocks of these smaller companies because of what happened. Basically, Reddit trolled Wall Street so hard that some companies lost millions of dollars.