Why Do Chart Prices and Execution Prices Differ? Causes and Checks

Finding that a fill does not exactly match the number shown on a chart does not necessarily mean the platform made an error. A chart shows a bid, ask or midpoint from a particular quote source at a particular time. Execution occurs when an order reaches the execution system and is matched against quotes then available. Quote type, spread, latency and liquidity all matter.

First Check Whether the Chart Shows Bid or Ask

Forex and CFDs commonly have both a bid and an ask, with the difference being the spread. Many charts display only the bid by default, while a buy is usually filled at the ask and a sale at the bid. For example, if the chart bid is 1.1000 and the ask is 1.1002, a buy near 1.1002 is not inherently abnormal. You can enable an ask line in the platform settings and check how the order-confirmation page defines its quote. Quotes and trading mechanics differ across asset classes.

Quote Refresh and Execution Do Not Happen at the Same Instant

When prices move quickly, market data takes time to travel over the network, refresh the interface and route an order. You might see 1.1000 when clicking, while the executable quote may have changed to 1.1003 by the time the order arrives. That creates positive or negative slippage. The difference may be more pronounced around news releases, opens, closes or periods of insufficient liquidity. A market order generally fills at the price then available; it does not guarantee the level shown on a particular chart candle.

Other Easily Overlooked Causes

Different data sources, contract types and account servers may provide different quotes. A chart may show a spot reference price while the trade is in a future, CFD or product with different contract specifications. Chart time zones, candle-close rules and corporate-action adjustments can also affect visual comparisons. Check the instrument code, contract month, trading hours, account type and whether historical candles are built from bid prices.

How Can You Check Whether a Difference Is Reasonable?

Keep the order ID and fill confirmation. Compare order submission and execution times, bid and ask, spread, order type and slippage policy; if needed, export tick quotes or execution records from the platform. Try to compare the same account, instrument and quote source rather than relying only on screenshots. If a difference exceeds the platform's disclosed rules, submit the timestamp with its time zone and the order ID to customer support and ask for an explanation rather than attributing the cause to a single deviation. Rules differ by instrument, jurisdiction, platform and broker. This article is for general education and is not investment advice; trading can cause losses.