Done that a few times - joined you on SYNA at 20.84 and let go of SHOP for a small profit yesterday. Should have posted the SHOP sale real time for the belief factor, but thankful to be out of it for now nonetheless.
Hey Zeev...I've had my share of those also...once when I went in to change a limit order to buy 2000 shares of an oil stock around $10, I put in the 1 but in error never took out the 2, thereby changing the order to 12000 shares! And I fillled all 12k, though managed to make out okay over the next few days on it, but surely scared me in a big way! HA!! tuna