I can't see how selling stock that you didn't buy could do anything but complicate matters. One of my brokers (the same one I mentioned in a previous post) once accidentally placed a $40K buy order and fill into my account. The transactions appeared in my execution log as I watched, and I called them within minutes, but this was already after hours and nobody looked at it so I had to badger them again the next morning. I was pretty sure it was a mistake and not fraud because the timestamps were several hours old, so it seemed that someone doing end-of-day cleanup, maybe moving something from a margin account to a cash account, mistyped an account number. And that is indeed what happened. Still, it blew out my margin and I decided to sell one of my holdings - but not the stock that had landed in my account - at a loss, because being unable to daytrade the following day would be worse than that loss. (As compensation, they offered to refund the commission on that trade.)
