Education

Why the Price on the Screen Is Not Always the Execution Price

By Walid Mograbi · 2026-04-08 · 2 min read

Fast markets do not promise that the displayed price will still exist by the time your order fills.

Why this lesson matters

Fast markets do not promise that the displayed price will still exist by the time your order fills.

The core idea

• The price you see on the screen is not a promise of execution, because the market can move before the order reaches the book.
• A market order focuses on speed, but it does not guarantee the last price you saw before sending the trade.
• The more volatility rises or liquidity weakens, the more the execution price can drift away from the expected price.

Practical example

When a sharp move happens between your click and the fill, a market order may fill far away from the screen price you saw.

Common mistakes to avoid

• Assuming the screen price is locked
• Ignoring execution drift
• Treating market speed as price certainty

What to do next

It helps you understand why execution can differ from the displayed price and choose orders more consciously.

Important caution

Do not assume the last visible price is the price you will actually get.

Further reading

• https://www.investor.gov/introduction-markets/how-markets-work/types-orders
• https://www.investor.gov/index.php/introduction-investing/investing-basics/glossary/market-order
• https://www.finra.org/investors/investing/investment-products/stocks/order-types