"That crucial piece of financial market plumbing [clearinghouses] was in focus after Robinhood and a number of other brokers on Thursday outraged individual investors — and a few lawmakers — by restricting trading in highflying GameStop Corp. GME, 65.92% and shares of other heavily shorted companies.

While the action sparked a number of conspiracy theories centered on alleged collusion between hedge-fund managers and brokers, the brokers appeared to have little choice as the clearing house, spooked by volatility in GameStop and other shares, increased the amount of collateral the brokers had to post to ensure the trades would be settled.

While to an investor, making a trade might look like an instantaneous transaction, there’s more to it. In fact, it usually takes two days for the trade to settle and the money and the securities actually change hands.

Clearinghouses stand between buyers and sellers, ensuring that the trade is completed should one side default. Clearinghouses require their members — banks and brokers — to be well-capitalized, to deposit collateral and to pay into a default fund.

When trading gets volatile, the risk of default rises, especially when investors are buying shares on margin or with money borrowed from their broker. Clearing firms understandably get nervous and can require brokers to increase the amount of collateral they must pony up to clear their trades."

I am deeply saddened to report that once again, I am right. Something something occam's razor; ease up on the kool-aid once in a while.

https://www.marketwatch.com/story/gamestop-frenzy-puts-clearinghouses-in-spotlight-as-investors-weigh-systemic-risk-fears-11611950283

Basically: there wasn't some grand conspiracy at work. Stock clearinghouses would've needed a massive increase in collateral from brokers due to the volatility (something else I had/have concerns about) of the market. A massive increase due to a few stocks, mind you. I assume the options would've been: 1. take the hit (which, again, for a few stocks, is a bit ridiculous), 2. pass on the cost to traders (hello per-trade commission fees) or 3. let things cool down a bit.

Naturally, 1. was extremely unlikely, 2. given that almost every broker has eliminated regular trading fees, would be pretty hard to flip back on just because of this, so brokers went with option 3.