Trading psychology: FOMO, revenge and discipline

It's not the market — it's us

Most traders lose money not for lack of knowledge but because they break their own rules. On paper everything is clear: entry, stop, target, size. But in front of the screen fear, greed and pride take over. All the maths from the previous lessons — position size, R:R, the stop-loss — only works if you follow it.

The human brain was not built for markets. Fleeing danger fast, following the crowd, refusing to accept a loss — useful instincts in everyday life. In the market these are exactly what costs the most. You cannot remove them, but you can recognise them and fence them in with rules.

Six main traps

1. Loss aversion

Loss aversion means a loss hurts more than a gain of the same size feels good. In the research of psychologists Kahneman and Tversky the difference came out at roughly two times; the exact figure varies from person to person.

In trading it leads to two mistakes:

• Holding losers. Moving the stop lower, waiting for "it'll come back" — because selling makes the loss "real".
• Selling winners too early. The urge to "lock in" a small profit quickly.

The result: small wins and big losses. That is system C from the R:R lesson: a 90% win rate, yet a shrinking account.

Rule: the stop is set before entry and only moves in the profitable direction. The target and the partial-exit plan are written down in advance too.

2. FOMO — fear of missing out

FOMO: the stock has already run, everyone is talking about it and you jump in without a plan.

The stock ran from $50 to $60 (+20%). A FOMO buyer at $60 has a logical stop under the base at $51.60 — $8.40 of risk per share. A trader with a plan waited for the retest and bought at $53, with the same $51.60 stop — $1.40 of risk.

With $100 of risk the FOMO buyer can take just 11 shares, the planned trader 71. If the FOMO buyer took the "usual" 71 shares, at the pullback low ($52.80) he is down 71 × $7.20 = $511.20 — five times the planned risk. He sells in fear — right before price rises again.

Rule: no plan, no trade. A missed opportunity is not a loss. If price has already left, set an alert and wait for the retest.

3. Revenge trading

Revenge trading means jumping straight back in after a loss, with a bigger size, to "win it back". It is the most dangerous trap, because the deeper the loss, the harder the way back:

Recovering from −10% takes +11%, from −20% +25%, from −30% +43%. After −50% you have to double the account.

Here is what it looks like in one evening:

Account $10,000, normal risk $100. Both traders lost their first two trades (−$200). A hit the daily limit and stopped. B doubled the risk after every loss: $200, $400, $800. All three of those trades lost too, and B's evening ended at −$1,600 (−16%). Even one win would not have saved him — as the size grows, each loss swallows the one before.