This isn't just about margin, absolutely, this is about all sorts of order flow agreements, credit lines and clearing agreements that break down when your entire customer base has decided they all want to go long the same incredibly volatile stock at the same time.

>"If you wanna buy GME you gotta have the cash in your account to cover it".

That's great, but that isn't the only relationship in this agreement, RH has agreements with its brokers about capital requirements. It's fairly likely that the attitude of "You need to have cash on hand for everything" basically means "You're done". That's the entire point of these risk management strategies - you are covered for what might reasonably happen so that you're making efficient use of capital.