Behavioral trading glossary

After-loss tilt is the measurable degradation in a trader's decisions immediately following a losing trade, usually visible as faster re-entries, larger size, and worse outcomes than the trader's baseline.

Anchoring is the bias that makes the first number a brain sees disproportionately influence subsequent judgments, surfacing in trading as treating an entry price, prior high, or round number as if it had predictive meaning.

Confirmation bias is the tendency to seek, weight, and remember information that supports an existing position while discounting evidence against it, which in trading produces traders who research only the upside of an idea they already hold.

The disposition effect is the documented tendency to sell winning trades too early and hold losing trades too long, named by Shefrin and Statman in 1985 and measured by Odean across thousands of brokerage accounts.

FOMO in trading is the urge to enter an extended move late, driven by watching others profit, and it shows up as poorly-priced entries on already-trending instruments.

The gambler's fallacy is the mistaken belief that an independent outcome becomes more likely because of a recent streak against it, surfacing in trading as the conviction that a string of losses makes the next trade due for a win.

Loss aversion is the documented tendency, named by Kahneman and Tversky, for the pain of losing a given amount to be roughly twice as motivating as the pleasure of gaining the same amount, which biases traders toward decisions that reduce short-term pain at the cost of long-term return.

Overconfidence is the well-documented tendency to overestimate one's own skill, knowledge, or accuracy, which in trading consistently produces excessive turnover, oversized positions, and the worst net returns in the Barber and Odean studies.

Revenge trading is the act of placing a new trade specifically to recover from a recent loss, usually in the same instrument and direction, often within minutes of the original loss closing.

The sunk-cost fallacy is the tendency to weight money already spent as a reason to keep spending, surfacing in trading as adding to a losing position because the trader is already in rather than because the new entry has independent merit.

The behavior gap is the persistent difference between an asset's returns and what investors actually earn from it, caused by buying high in euphoria and selling low in panic.

Cutting losses is the discipline of exiting a losing trade at the pre-committed stop without negotiation, the single most reliable predictor of long-run survival across every academic and practitioner study of trader outcomes.

Hold-time discipline is the practice of holding winning trades longer than losing trades, the opposite of what most untrained traders do by default.

Overtrading is taking more trades than the trader's edge justifies, usually driven by boredom, screen time, or the urge to be active rather than by setup quality.

Partial exits are pre-planned reductions of position size at successive price targets, banking some profit at each level while letting the remainder run, which lowers behavioral pressure without surrendering the trade's upside.

Plan adherence is the degree to which a trader's actual behavior matches the rules they pre-committed to, measurable as a percentage or score across a defined window.

Stop discipline is the practice of exiting a trade at the price the trader committed to before entry, measured by the gap between planned and actual stop loss across a sample of trades.

A trailing stop is an exit order that moves with the trade in the direction of profit but never against it, locking in gains as a position runs while preserving the original downside cap if it reverses.

Drawdown is the peak-to-trough decline in account equity over a defined window, expressed as a percentage of the prior peak, and is the single most reliable predictor of whether a trader will quit a strategy.

The Kelly criterion is a mathematical formula for the optimal fraction of capital to risk per bet, derived by John Kelly in 1956, that maximizes long-run compounded growth given a known edge and a known win-loss payoff.

Max loss vs max gain is the ratio of a trader's largest single loss to their largest single gain, a quick read on whether one bad trade can erase weeks of good ones.

Position sizing is the decision of how much capital to commit per trade, conventionally expressed as a percent of account equity risked between entry and stop, and is the single biggest lever a trader has over long-term outcomes.

Risk of ruin is the mathematically calculated probability that a trading account will lose enough to be unrecoverable, given the strategy's win rate, average win and loss size, and position sizing.

Size discipline is the practice of risking a roughly constant percentage of account on every trade, regardless of conviction or recent results.

The Calmar ratio is the strategy's annualized return divided by its maximum drawdown over the same period, which expresses the trade-off traders care most about in plain terms: how much return per unit of worst-case pain.

Edge is the measurable positive expected value a trader earns per trade, after costs, that comes from any repeatable advantage in setup selection, execution, or risk management.

Expectancy is the average dollar amount a trader expects to win or lose per trade across a large sample, computed as (win rate × average win) minus (loss rate × average loss).

Maximum Favorable Excursion and Maximum Adverse Excursion are, respectively, the highest unrealized gain and the largest unrealized loss a trade reaches between entry and exit, and together they grade exit quality independently of final P&L.

The payoff ratio is the average size of a winning trade divided by the average size of a losing trade, and it is the single most direct measure of whether a trader is letting winners run and cutting losses short.

Profit factor is the ratio of total gross profits to total gross losses over a window, a quick read on whether a strategy makes more than it loses across the trades it took.

R-multiple expresses a trade's profit or loss as a multiple of the dollar amount the trader risked on that trade — a 2R win is twice the risk, a 1R loss is one full risk unit.

The recovery factor is net profit divided by maximum drawdown over the same period, expressing how many drawdown-equivalents of profit a strategy has produced and answering the practical question of whether the trader has been paid for the pain.

The Sharpe ratio is the most widely used measure of risk-adjusted return, calculated as the strategy's excess return over the risk-free rate divided by the standard deviation of its returns; higher is better and the same return at lower volatility produces a higher Sharpe.

The Sortino ratio is a refinement of the Sharpe ratio that uses only downside deviation in the denominator, so upside volatility no longer counts against the strategy and the metric reflects what most traders actually care about: how rough the bad days are.

Win rate is the percentage of trades that close profitably, useful but routinely misinterpreted as a measure of skill or strategy quality.