Education

Common Mistake: Placing a Market Order Before the Session Opens

By Walid Mograbi · 2026-07-04 · 2 min read

A market order may execute quickly, but before the market opens the displayed price is often only a pre-open quote. Review session timing, liquidity, and price protection before sending the order.

Common Mistake: Sending a Market Order Before the Market Opens

This lesson is about why a market order can feel immediate but still produce an unexpected entry price when placed before the session starts.

Core Lesson

A market order is designed to execute quickly, not at a guaranteed price. Outside regular trading hours—especially in pre-open periods—the displayed quote may not represent the price you will actually get.

Why this happens

In volatile periods or weak liquidity, an order can be filled in multiple parts at different levels. The execution price path can drift, and the final fill can be worse than the first visible level you noticed.

The three questions to ask first

• Is the order going in during a non-standard session (pre-open or after close)?
• Is the position size large compared to the asset’s current liquidity?
• Instead of market, would a limit order with a minimum acceptable price give better control?

Practical check before news or pre-open entries

Before sending any order in news windows or before the open, define the order type, size, and acceptable fallback price first. This does not add complexity; it adds repeatability and reduces guesswork.

Benefit to your process

This quick check helps you avoid execution surprises and keeps control over your entry conditions rather than merely reacting to whatever appears on screen.

Keep this warning in mind

Pre-open displayed prices are not confirmed execution prices. Once the session opens, the opening print can be different from what looked available moments earlier.