> Apple trades an order of magnitude more per day than any of the stocks that were halted. Somehow the clearinghouses have no trouble with the Apple volume.

The clearinghouse had no problem with GME volumes either. They just required collateral. Had Robinhood not been able to meet its obligations yesterday and thus gone under, that collateral would help settle its trades with other brokerages.

Collateral requirements are re-calculated daily. That means there is risk between the last collateral calculation and where an asset is trading today. That risk is a function of volatility. So for a stock like Apple, the DTCC may only require 2% of the value of the trade be put up as collateral. For a stock like GameStop, it may require 100%.

Firstly, this isn't true. Just this week AMC was trading tens of billions of dollars worth of shares per day, which is about equal to AAPL. GME is seeing >twice as much.

Second, the insane amount of volatility and concentration in these tickers makes the clearinghouses charge the brokerages way way more. You have fees (quoted in %) for expected change and also lack of diversity.

It’s because considerably less capital is required to clear an Apple trade, because it is a much less volatile stock.