Slippage

Slippage is the gap between the price quoted when an order was sent and the price at which it was filled. Negative slippage (worse fill) is more common during high volatility or low liquidity; positive slippage (better fill) happens when price moves favorably between order placement and execution. Market orders, stop-loss triggers, and orders placed during news releases are the most slippage-prone. Limit orders eliminate negative slippage by guaranteeing the price but accept the risk of partial or non-execution.