Behavioural effects in trading
Patterns in how people react to gains, losses and each other. They shape the decisions of individual traders, and sometimes of whole markets.
What behavioural effects are.
Repeatable patterns in how people behave around money and risk.
Behavioural finance studies how real people make financial decisions. It finds patterns that differ from the purely rational choices older models assumed.
Several of these patterns are called effects. They describe what people tend to do, often without noticing, when they face gains, losses and crowds.
Effects overlap with biases. A bias is an error in judgement. An effect is the behaviour that results, which you can see in your own trading record.
Five effects traders should know.
Each has been described by researchers, and each shows up in trading.
The disposition effect.
Selling winning positions too soon and holding losing ones too long. Hersh Shefrin and Meir Statman described it in 1985.
The endowment effect.
Valuing something more because you own it. An open position can look more promising than the same trade not yet taken.
The house money effect.
Taking bigger risks with recent profits than with your original money. Profits in your account are real money, with the same value.
Herding.
Doing what others are doing because they are doing it. In markets, herding can carry prices further than the news alone would.
The Dunning-Kruger effect.
People with limited skill in an area tend to overrate it. A new trader after a few early wins is especially exposed.
The disposition effect in numbers.
Suppose a trader holds two positions of 0.1 lots each, both worth $1 a pip.
Trade A is 40 pips in profit. Trade B is 40 pips in loss. Taken together, the two trades are level.
The trader closes A to lock in $40, and keeps B open in the hope it recovers. B keeps falling, and the trader finally closes it 80 pips down.
| Trade A | Trade B | |
|---|---|---|
| Size | 0.1 lots ($1 a pip) | 0.1 lots ($1 a pip) |
| At the moment of choice | +40 pips | −40 pips |
| What the trader did | Closed it | Held it |
| Result | +$40 | −$80 |
The net result is a $40 loss, from a moment when the two trades were level. A stop and target set at entry would have taken the choice out of the moment.
How to manage them.
Habits that help you notice these effects, and stop them steering your trades.
Set exits before entry.
Choose the stop and the target when you open the trade, and let the orders do the work.
Risk the same share every time.
Risk a fixed share of your account on each trade, whether you are up or down for the day.
Treat profits as your own money.
Once a gain is in your account, it deserves the same care as any other money.
Check the crowd, then check your plan.
Notice when you want a trade because everyone else is in it. Ask whether it meets your own rules.
Review your exits.
In your journal, compare how long you hold winners with how long you hold losers.
Common mistakes.
Where these effects most often show up in trading.
Closing winners early to feel safe. It can leave the gains too small to cover the losses.
Raising size because you are trading with profits. A loss on that money is still a loss.
Following a popular trade without a reason of your own. The crowd can turn quickly.
Mistaking a few wins for mastery. A short run of results says little about skill.
Questions, answered.
What traders ask most about behavioural effects.
01What is the disposition effect?
02Is herding always bad?
03What is the house money effect?
04How does the Dunning-Kruger effect apply to trading?
05Can I practise managing these effects?
Practise with fixed rules.
Trade a fixed plan on a free MT5 demo and compare how you handle winners and losers before you trade real money.
Trading CFDs on a live account puts your capital at risk and you can lose money. A demo does not.