To be fair, Interactive Brokers also halted these transactions, and they're well-known for catering to hobbyist and professional traders. Granted, they're more

To be fair, Interactive Brokers also halted these transactions, and they're well-known for catering to hobbyist and professional traders. Granted, they're more mainstream than dedicated day-trading brokerages, but some of those depended on clearing houses that also decided to halt sales.