Very clear explanation. Basically, if you're creating massive volatility, you're causing problems for someone else, and eventually, that someone else is only going to be prepared to do business with you on terms which reflect the cost of that inconvenience. https://twitter.com/zGuz/status/1354854476801302528

To the extent this is Robinhood's fault (which might be quite a bit), it's because they marketed stock trading as if it were a frictionless video game and it's not; clearing and settlement is hard work and relies on people acting sensibly. When they don't, the clearers get mad.

(a useful financial rule of thumb is that if you ever need to find out any technical details about clearing or funding, you should stop doing the thing you're doing because something has gone badly wrong)