The fill price differs from the chart price more often than people notice

[Amanhasnoname]

Most charts plot the bid. A buy order fills at the ask, which sits a spread above. So a long trade entered at a chart price of 1.0850 can fill at 1.0851 or 1.0852 without any slippage at all, simply because of the spread.

The reverse matters on exits. A long position closes at the bid, which matches the chart, while a short position closes at the ask, which sits above the line on screen. That means stops on short trades trigger earlier than the chart suggests, since the ask touches the stop level before the bid does.

This creates a nasty illusion in backtests and chart reviews. A candle high that "just missed" a short stop on the bid chart might have clipped it on the ask. Reviewing trades without the ask line enabled makes stops look unlucky when they were simply hit.

Turning on the ask line in the platform settings is a two-second fix, and it clears up many "the stop was hunted" arguments instantly.

Is the ask line always displayed on charts, or does it mostly stay hidden?