I have Schwab (TD Ameritrade conversion) & Interactive Brokers and Interactive Brokers is very good even at illiquid securities. My hunch is most of these trading brokers (futures, options, international, etc.) are a lot better than these investing brokers. When my account was at TD Ameritrade (and Datek before that) they did a good job at mark-to-market.
I am with Fidelity but Fidelity and some other companies have this weird rule where you place an order and that order expires at 4PM. You have to replace the order for after market hours So I was leaning towards Schwab because you place the order and it will be filled within any market premarket or after market on all of them. I will look into Interactive
For anyone who wants to know: the sell off did concern Mark Stevens selling $20m in shares, probably actioned by Merrill Lynch. This is why fundamental analysis matters as well as technical. www.sec.gov/Archives/edgar/data/1045810/000104581024000298/xslF345X05/wk-form4_1728682961.xml