https://www.vice.com/en_us/article/wx8bpx/experts-say-robinhood-gamestop-fiasco-likely-caused-by-lack-of-cash

After a day of being raked over the coals by lawmakers and users, the stock trading app Robinhood put out a vague statement Thursday attempting to explain why it stopped allowing its users to buy GameStop, AMC, Nokia, and other “meme stocks” that were skyrocketing in price.

A dominant theory among some investors was that Robinhood stopped allowing people to buy GameStop stock in order to benefit firms such as Citadel, a company that pays Robinhood for information about its users’ trades and recently helped bail out a company called Melvin Capital from the short-sale positions it had taken on GameStop. Regulatory experts, however, say that this doesn’t seem to be the reason. As they see it, the likeliest explanations for Robinhood defenestrating itself by breaking trust with its user base are less nefarious but perhaps more embarrassing, and suggest that the stock trading platform may not have had enough cash on hand to stay within regulatory rules for brokerage firms.