A post-mortem checklist for bad trades

Not every loss is a lesson. Some losses are just losses — variance expressing itself in your account. The problem is that it is very difficult to tell, in the moment after a bad trade, which category you are looking at.

A post-mortem checklist is a structure for making that distinction clearly and without panic. It slows down the review process, separates the facts from the emotion, and asks whether anything about your process actually needs to change.

Used well, it turns a bad trade into information. Used poorly — or not used at all — the same trade becomes either a spiral of second-guessing or a data point that disappears without leaving anything useful behind.

The three types of loss

Before running any checklist, it helps to name what you are looking for. Losses fall into roughly three categories:

Thesis failure. The reason you entered the trade turned out to be wrong. The macro view was off, the catalyst did not materialize, the sector rotated the wrong direction. The thesis failed and the position lost money as a result.

Execution failure. The thesis may have been correct, but the trade was managed poorly. You entered too early or too large, did not set a stop, added to a losing position, or exited at the wrong time for an emotional rather than structural reason.

Variance. You followed your process. The setup was valid. The stop was placed correctly. And the market still moved against you in a way that hit the stop before the thesis could play out. This is a loss that belongs in the normal distribution of your strategy’s outcomes.

The first two are fixable. The third is not — and trying to fix it often makes things worse.

The checklist

Run this after any significant loss, or at the end of a sequence of losses if they have clustered together.

Was the thesis explicit before entry? Could you have written it in two sentences? Did you know what would have to be true for the trade to work, and what would have to happen for it to be wrong? Vague thesis = execution by instinct = no post-mortem is possible.

Was invalidation defined before entry? Where was your stop? Was it placed based on structure, or placed arbitrarily? A stop that exists only as a mental note is not a stop.

Was size appropriate for the setup? Were you sized correctly given the variance of the instrument and the quality of the setup? Did you size up because the setup looked compelling, or did you follow a consistent rule?

Did execution match the plan? Did you enter at the level you planned, or chase the entry? Did you exit as planned, or move the stop? Did you add to the position after it started losing?

Was the loss within the expected range for this type of setup? If you size 1% risk per trade and the trade hit your stop, the loss is inside normal variance. If the loss was significantly larger than planned, why? Slippage, moved stop, or added size?

Is this loss part of a pattern? Have you lost on similar setups recently? Is the same thesis failing repeatedly? Is the same execution mistake appearing in multiple trades? One loss is a data point. Three similar losses in a row is a pattern worth investigating.

What to do with the answers

If the thesis failed: Review whether the category of setup is still valid or whether market conditions have changed. Do not immediately abandon a thesis after one failure — but do ask whether the macro context that originally supported it still exists.

If execution failed: This is the most actionable category. Identify the specific moment where the plan was deviated from and ask why. Usually it is a behavioral cause: fear, greed, boredom, or the impulse to recover a recent loss quickly. Name it specifically.

If it was variance: Log it and move on. Do not change your process in response to a loss that your process handled correctly. This is harder than it sounds.

What not to do

Do not run a post-mortem immediately after the loss closes. The emotional intensity is still active and it distorts the review. Wait until the next day at minimum.

Do not use the post-mortem to punish yourself. The goal is information, not self-criticism. The question is not “how could I have been so stupid” — it is “what does the process need, if anything.”

Do not react to a single outcome. Review across three, five, or ten trades before changing anything structural. Markets produce variance. A one-loss reaction to variance is itself a process failure.

The point of the exercise

A post-mortem is not designed to prevent losses. Losses are unavoidable. It is designed to make sure that each loss, over time, contributes to improving your judgment — rather than just accumulating as unexamined damage to your account and your confidence.

The traders who survive in the long run are not the ones who avoid losses. They are the ones who are honest about what caused them.