Want to see two absolutely crazy, shady, frustrating charts? (warning: they're confusing, I'll explain)
These charts, which show stock price, volume, short interest, and short volume, tell the story of what happened over the past few days.
Left: $AMC, Right: $GME
On Wednesday night, Robinhood and several other apps limited trading of a number of tickers to just a few shares & options. You could sell as many as you owned, but you couldn't buy any more than a couple of each ticker. It included $AMC, $GME, and a few others…
They did this because their clearing houses increased liquidity requirements more than a hundred percent. A clearing house, if you’re wondering, is what settles all of the trades made during each trading day.
So, when you buy or sell a stock, you might see the cash or the stock in your account immediately. In the background, however, it’s a lot more complex: these clearing houses settle up the books between each other to make sure everyone is squared up properly.
These clearing houses have "liquidity reqs" which are set by regulations and other partners; they literally need to have a certain amount of cash on hand for different securities.
On Wednesday night, the requirements for certain extremely volatile stocks like GME skyrocketed.