Frustrating experience today with E-Trade. Opened a 1,000 share short position this morning as a quick scalp. Tried to cover 2 minutes later at a 20 cent profit, but accidentally shorted another 1,000 shares. No problem, I'm short 2,000 shares and the price continues down and I try cover the entire 2,000 shares at a 50 cent profit. The system rejects my order 3 times in a row saying insufficient funds. I end up covering 1,600 shares, but can't cover the remaining 400. I have a longer term long position which is currently under water. Understandably, this reduces my buying power, but I'm trying to cover a short not add a new long position. I can't believe the system would let me in a trade and then not let me out a few minutes later. I call E-Trade customer service twice and each time am put on hold for 15 minutes while the guy talks to his supervisor. They say I'm "boxed in" and can only resolve it by selling some of the long position or waiting until tomorrow when my buying power is renewed. I talk to the supervisor and he basically says tough sh*t. Do all brokerages operate like this? Am i being unreasonable to expect that the software would not let me in a trade (or at least warn me) that I won't be able to get out?