In simple terms
Slippage is the difference between a reference price selected before the analysis and the price actually obtained. It can be adverse or favorable, depending on the order side and the direction of the difference.
How the term is used
Saying “I got slippage” without naming the benchmark makes the comparison ambiguous. The reference may be the quote at submission, the midpoint, the arrival price, or another stated value. When an order receives several fills, the execution price must be weighted by quantity. Spread, latency, and market impact may contribute to the outcome, but they are not synonyms for slippage.
For formulas, partial fills, and operational checks, see Slippage.
Limit
The price shown on screen may not be tradable for the entire quantity and may change during routing. No order type simultaneously eliminates slippage, non-execution risk, and opportunity cost.
Sources
- U.S. Securities and Exchange Commission, Investor.gov, Executing an Order — explains, for U.S. retail stock orders, how quoted size, routing, and delay may produce a price different from the one observed.
- U.S. Securities and Exchange Commission, Frequently Asked Questions: Rule 605 of Regulation NMS (April 1, 2026) — defines timestamps and price and fill statistics for covered U.S. orders; it is staff guidance, not a universal slippage measure.