I have been an active trader since the early nineties when data feeds were very expensive and 20 dollar commissions were considered discount. I was under the impression that you could not hold a long and a short position of the same stock in the same account. In the early days of online trading in order to cover you just hit buy. I took a 1000 share position on WMT on a MOO this morning. It executed a 45.60. It moved my way and I decided to cover it at 45.53. But my buy and cover buttons are side by side and I accidentally hit buy. I bought 1000 WMT at 45.53, so I was holding two positions. Since the stock was then trading around 45.60, I put in a sell order at 45.58. I got an error message saying something to the effect that in the box you had to cover your short first. By this time the stock had moved up. I covered at 45.70. Then I sold at at 45.75. Somehow, it did not work out too badly as I cleared 140 dollars in my less than six minutes of confusion. My question is, is anyone taking both sides of the same stock intentionally?