Great thread & very good responses. I have not read "Trading in the Zone" but plan to after the numerous recommendations. I have often felt the same way when ready to pull the trigger. Many have already touched upon position size & risk tolerance but I'd like to add my 2¢. Think about the trade setup for a moment. If you were waiting for a stock to trade up to a point of resistance you've identified and it does trade up, then you have to be ready to short into the strength. This can be difficult because you are shorting into a rising market with the possibility of it moving against you as you enter the trade. After all, it's running up at the time you enter the trade. So your emotions get in the way & inhibit you from thinking clearly & following the original trade plan which says that you've seen this before and you expect the reversal. If you wait for it to reverse and start the anticipated move, you may miss the ideal entry point. If you chase it and if it reverses a bit because you have a less than ideal entry point, you will probably be more inclined to dump the position when you really shouldn't. To help with this problem it is imperative to keep the trading time frame in constant focus. It may look like a great entry point for a swing trade, but bad for an intraday trade. If you keep in mind that you're swing trading the stock, then always evaluate the trade based on that premise. Your position size must also be adjusted according to the time frame & your pre-defined stop loss.