Chart feed versus execution feed, are they the same?

[Amanhasnoname]

Some brokers show one price stream on the chart and use a different one for order handling. The two usually agree, but in fast markets they can drift apart by a pip or more.

Charts might be built from a bridge feed that smooths or throttles quotes, while the execution engine sees the raw liquidity stream. A trader clicking on the chart price may find the fill comes from a different price entirely.

Spotting it takes careful comparison. Run a screen recording during a news event and compare the price shown at click time with the fill price. If the difference regularly exceeds spread and normal slippage, something is off.

Third-party charting platforms add another layer. A chart from a data vendor will show different ticks from the broker's own feed, so signals built on the vendor chart may not match what the broker prices.

Matching the data source to the execution venue is the safest approach. Signals that depend on exact levels should be calculated on the same feed that fills the orders.

Has a mismatch between the chart feed and the fill price ever been noticed, and how large did it get?