Loss aversion: why a loss hurts about twice as much as a win feels good

[Shadow Trader]

Behavioural economists have measured it repeatedly: losing a sum of money feels roughly twice as bad as gaining the same sum feels good. The exact ratio varies between studies, but the asymmetry is robust.

For a trader, the consequences are practical. A scalper holding a loser feels the pain of realising it, so the stop gets moved. A scalper holding a winner feels the pleasure of locking it in, so the target gets cut short. The result is a payoff profile that nobody designed: small wins, large losses, and an expectancy that quietly turns negative.

Knowing the bias doesn't remove it. What helps is moving decisions out of the moment: stops and targets placed at entry as hard orders, position sizes small enough that a single loss doesn't sting, and a review process that grades decisions by rule-following, not by outcome.

Some traders also reframe by thinking in R-multiples. A loss of 1R isn't an emotional event, it's a cost of doing business, like rent.

A tiny self-test: look at the last 100 trades and compute the average winner and the average loser in R. If the average loser is bigger than the average winner while the strategy was designed to have the opposite profile, loss aversion has probably been editing the exits. It's a five-minute check, and the answer is often uncomfortable.

Some traders go a step further and tag each exit as "planned" or "discretionary" in the journal. When the discretionary exits are mostly early closes on winners and late closes on losers, the bias has a fingerprint.

Where does loss aversion show up most in personal trading: cutting winners, holding losers, or avoiding the next entry after a loss?