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Glossary / Market structure

Pre-market

Definition

Trading before the regular session opens.

Why it matters

Thin liquidity and wide spreads make pre-market fills unreliable, so many journals separate pre-market results entirely.

Example

A stock that gapped up 8% pre-market on 200,000 shares is trading far thinner than it will after 09:30, so spreads and slippage are much wider.

How to track it in a journal

TradeStack calculates the core performance numbers — win rate, average win and loss, profit factor, expectancy, drawdown and consistency — automatically from imported trades, so pre-market stops being something you estimate and becomes something you read.

Related terms

Slippage
The difference between your expected fill price and the price you actually get.
Spread
The gap between the best bid and the best ask.
Liquidity
How much size a market can absorb without moving price.
Volatility
How much price moves over a given period.

Keep reading

Trading journal guides
Expectancy, profit factor, drawdown, backtesting and the PDT rule.
Free trading calculators
Position size, risk-reward, expectancy and options profit.
Expectancy calculator
Expected profit per trade from your own numbers.
Broker CSV export guides
Step-by-step exports for Tradovate, NinjaTrader, IBKR and more.
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