Journalling and review: the only mechanism that improves judgement

Without a record, you learn nothing, because memory rewrites your reasons to match the result. This is the cheapest edge available and almost nobody takes it.

The problem memory creates

Ask someone why they bought something that went up and they will describe foresight. Ask about something that went down and they will describe bad luck. Both accounts are sincere and both are reconstructed after the fact.

This is not dishonesty, it is how memory functions. Recall rebuilds the past to be consistent with what you now know. The consequence is that without contemporaneous notes, you cannot tell a sound process from a lucky one, and therefore you cannot improve either.

What to record, at the moment of the decision

Six fields, two minutes. If it takes longer you will stop doing it, and a journal you abandon is worth nothing.

Separating good decisions from good outcomes

This distinction is the entire point of reviewing, and it is the one people skip.

• Good decision, good outcome. The process worked. Note what you did and repeat it.
• Good decision, bad outcome. Sound reasoning, correct sizing, unlucky result. Change nothing. Most people change everything here, which is how a working process gets abandoned.
• Bad decision, good outcome. The most dangerous cell. You broke your rules and were rewarded. This is where habits that eventually destroy accounts are formed. Flag these deliberately.
• Bad decision, bad outcome. The cheapest lesson available. Name the specific rule you broke rather than concluding that you are undisciplined.

The monthly review

1. Read every entry from the month before looking at any performance figure.
2. Tag each into the four cells above.
3. Count the emotional states. What proportion of decisions were taken while rushed or excited, and how did those perform against the calm ones?
4. Check calibration. Of the decisions you rated eight or higher, how many worked?
5. Find the single most expensive mistake and write down the specific rule that would have prevented it.
6. Add that rule to your policy document. One rule per month is a substantial rate of improvement.

The quarterly review

Wider and less about individual decisions. Is the overall approach working, adjusted for how much risk it took? Are your winners large relative to your losers or are you cutting winners early? Which tier of the portfolio actually produced the returns? Are you following your own written policy, and where specifically are you not?

That last question is usually the most productive. Most people discover that they follow their rules on ordinary days and abandon them on the days that determine the year.

The patterns a journal reliably reveals

• Almost everyone finds their rushed decisions substantially underperform their calm ones. This is the most common finding and it is directly actionable.
• Most people find their confidence is poorly calibrated, which means sizing by conviction is sizing by noise.
• Many find their losses cluster into a small number of categories, usually two or three, which makes them fixable with specific rules.
• Many find their best returns came from a very small number of positions, which changes how they think about selling winners.
• Almost everyone finds they broke their own rules more often than they believed.

None of these findings require sophistication. They require having written things down, which is why it is simultaneously the cheapest and the rarest habit in the market.

Common questions

What should a trading journal contain?

Six fields written before the outcome is known: what you did, the real reason, what you expect, what would prove you wrong, your emotional state, and your confidence out of ten. Two minutes per entry.

Why separate good decisions from good outcomes?

Because randomness dominates single results. A sound decision can lose and a rule breaking gamble can win. Judging by outcome teaches you to repeat whatever was lucky, which is how habits that destroy accounts get formed.

How often should I review my trading?

Monthly for individual decisions and patterns, quarterly for whether the overall approach is working and whether you are following your own policy. Add one rule per monthly review.