In the past week or so I have noticed a huge change (for the better) in my P/L, as a result of standardizing my exits. Before they were pretty emotional. Anyway, this study pretty much sums it up:
An experiment by psychologists Radcliffe and Klein shows the harmful consequences of unrealistic optimism. Study participants were asked to estimate the odds of experiencing an adverse outcome, in which an "objective" estimate of the actual probability was known. Unrealistic optimists underestimated the odds of the adverse event compared to realistic optimists. They also allowed their unrealistic optimism to bias their judgment.
Here's the really important part:
When presented with information regarding how they could reduce the probability of the adverse event, they did not review it closely, compared to realistic optimists. They did not show proper concern and did not take necessary steps to protect themselves from the adverse event.
So, this could screw up one's trading in two ways: (a) taking a dubious entry, or more subtly, (b) hanging onto a trade too long. For example, not "taking what the market gives you". I say, if a trade moves a small bit in your favor, and then you see some mixed signals, get smaller, if not out.
There is also another part to exits that's easier said than done. What happens when there is a decent profit, but no mixed signals, no bad signs, everything is looking peachy? I say, sit tight, perhaps move your stops up. Again, easier said than done, but it's pretty key for me.