What Is Trading Psychology?
Trading psychology is the study of how decisions change under uncertainty, loss and fatigue. Much of what is attributed to it is better explained by position size and by the ordinary streakiness of any rule, both of which can be measured rather than felt.
The subject is real. Most of what gets filed under it is not psychology at all — it is an account under too much strain, and that has a number attached.
How it works
A rule was walked through 576 bars of the shared history — enter, hold to the stop or the target, then look for the next entry. 123 trades. 64 won, 59 lost.
Inside that, five losses in a row.
Nothing went wrong there. A run of five is what a rule near even money does over 123 attempts, and the person living through it has no way to distinguish it from a rule that has stopped working.
That is the actual problem this subject is about, and it is a statistics problem before it is an emotional one.
The market does not know
Measured across the whole history, one bar’s move predicts the next at r = +0.04, with a standard error of 0.04.
Inside one standard error of zero, which means no relationship you could act on.
And the trade after a loss won 28 times of 58. The trade after a win, 35 of 64.
48% against 55%, on samples where the ordinary error is about 6 points either way — so the two are not distinguishable, and there is nothing here that behaves differently because you just lost.
The revenge trade is not the market punishing you. It is you, changing the size, in a series that did not change at all.
Size is the whole lever
The same five-loss run, at two position sizes:
| Risked per trade | Left after five losses | Needed to recover |
|---|---|---|
| 2% | 90% | +11% |
| 5% | 77% | +29% |
| 10% | 59% | +69% |
| 20% | 33% | +205% |
One of those is an uncomfortable fortnight. The other ends the account.
The run was identical. Everything that differs between the two rows was chosen before any of it happened, which is what makes position sizing the psychological tool it is never described as.
A run is a period, not a moment
The five-loss run took 35 bars to happen — from the entry of the first to the exit of the last, about 6% of the whole history.
That is the part nobody prepares for. A losing run is not an afternoon; it is a stretch you have to keep following the same rule through, while it looks every day as though the rule has stopped working.
If each bar were a day, those five trades occupied about seven weeks.
And there is no gap inside it to recover in. On the slower view of the same history the rule held a position for 110 of 144 bars, re-entering as soon as it exited.
So a losing run is not five separate events with calm in between. It is one continuous stretch, and that is a different experience from the one a list of five results suggests.
The number worth knowing in advance is that one, not the win rate. A rule you would abandon after seven weeks of losing is a rule you cannot actually run.
What is actually left
Strip out the streaks and the sizing and there is a genuine residue, and it is worth naming precisely rather than dressing up.
Hindsight makes past charts look decidable. Every page on this site ends with a cut-off chart for exactly this reason — the feeling that you should have seen it is manufactured by seeing the outcome.
Effort feels like it should pay. Sitting still while nothing sets up is the correct action and it feels like failure, which is why over-trading is the most common way a good plan is abandoned.
A loss you chose feels worse than one you did not. Skipping a trade that would have won costs nothing and feels like nothing; taking one that loses feels like a mistake. That asymmetry pushes people toward inaction on the good setups and paralysis on the bad ones.
None of those are fixed by trying harder. They are fixed by deciding in advance, which is a procedure, and by writing it down, which is a journal.
A worked example
Set the size so that five losses in a row is dull. That is the test, and it is arithmetic.
Write the three prices down before entering.
Then do not review after a loss. Review on a schedule, which removes you from the selection.
And when a run happens, count it against the record, not against your character.
The original data
Across our study of 24,971 trading videos, 441 cover trading psychology. The median one gets 8,372 views, 72% never pass 50,000, and the median length is 19.8 minutes — the third-longest of any subject measured here, behind swing highs and lows and trading sessions.
The corpus carries description text for only 20 of those 441 — a thin sample — but across those 20, five mention invalidation, failure, or what a bad read looks like.
One in four, which is the fourth-highest rate in this glossary, behind stop loss, why traders lose money and position sizing. A subject about handling losses mentions losing more than most, which is the least surprising result on the site.
When it fails
You treat a streak as evidence
Five in a row is not a signal to change the rule, and 123 trades is barely enough to judge one at all. Changing after a run is how a record of one rule becomes a record of many rules with a few trades each — the failure the journal page describes.
The size was the problem all along
“I could not sit through it” and “the position was too large” are the same sentence. The first sounds like a personality; the second has a fix.
You measured discipline by feel
Discipline is countable. Trades taken that were not in the plan, over trades taken: a rate, and one you can watch fall.
You judged it at the edge
In the middle of the run, the five-loss stretch and a genuinely broken rule are the same experience. Which is why the response has to be a number decided beforehand, and not a judgment made here.
Related
Risk per trade is the setting that decides whether a normal losing run is survivable.
Why traders lose money is the arithmetic underneath the same question, with the costs put back in.
And the trading journal is the only way to tell a streak from a broken rule after the fact.
I do not think I have better emotional control than anyone else. What changed for me was making the position small enough that the outcome of any one trade stopped being interesting, and that is a slider, not a virtue. The times I have traded badly were almost always times I was carrying more than I could sit through.
— Michael Whitman, from this video
This page is educational, not financial advice. Test every idea on your own charts before risking money.