The trading strategy I'm using is to buy on a low channel breakout and sell on a high channel breakout. I'm intending for the strategy to only take long positions. However, over the past week the strategy has created a few short positions. I lost a significant amount of money today after the system took a short position and the stock's price jumped up 50%.

Also, I've noticed that using the manual trade ticket will inadvertently generate short positions even when I'm very careful to only sell the exact number of shares I'm holding.

Any thoughts on how I can prevent taking short positions going forward?

Are you using the IB broker provider?

Yes

You have to be careful with IB. There is no "Short", just "Sell".. If you have 10 shares and sell 20, you will be short 10 shares. I don't know the details, but you might be able to avoid the problem by configuring your Trading Options: do not Disable Portfolio Sync (unchecked).

This should be enough to prevent the problem for automated trades. If you manually enter trades, then this has no effect!

Alright, thanks.