I would like to be able to place an order and instead of specifying a finite quantity for size, have the ability to stipulate "All", such that my entire position is subject to the order, regardless of the size of the position. This would allow me to enter a position with a stop-limit order, e.g.,
Buy 1000 AAPL at 50 stop/50.25 stop-limit.
If I am not watching the screen, I will not know if my entire order is filled on a rapid move up in AAPL. The "All" stipulation for a sell order, or a stop loss, would allow me to simultaneously set a stop loss and a profit limit order at the same time I enter my entry/stop-limit order without knowing in advance if my entire entry stop-limit will be filled.