Course: Trading Mechanics·Lesson 2 of 2·6 min read·Last reviewed 9 May 2026

Understanding slippage

The gap between the price you wanted and the price you got — and when it matters most.

James Okonkwo
James Okonkwo

Ex-market maker · 11 yrs FX options · CMT

By the end of this lesson you'll be able to:

  • Define slippage in your own words
  • List two market conditions that widen slippage
  • Estimate slippage before sizing a trade

Slippage is a cost

Slippage is the difference between expected fill price and actual fill price. It is not a broker conspiracy — it is physics: thin liquidity and fast markets move between your click and your fill.

Slippage
The difference between the price you expected and the price you actually received on a fill.

Quiz — Test your understanding

1. Slippage most often increases when:

2. News events typically cause slippage because:

3. The best way to reduce slippage risk is often:

Glossary terms used in this lesson