Quote from 1a2b3cppp:
I have $300-400k with Scottrade, about 2/3 of which is currently invested and the rest is sitting in cash. Longer term stuff, dividends, swing trades, etc.
I also have around $50k with OEC in a futures account which I occasionally make withdrawals from into my bank account. It's way more than I need to cover the style of trading I do, I just like to have around that much in there.
I trust that both Scottrade and OEC will be there tomorrow so I'm not worried. I've been to Scottrade offices many times and I've talked to OEC on the phone many times.
I wouldn't keep any money with shady fly-by-night brokres or Forex brokers, though.