How are stop loss and take profit executed in a simulator?

Using the right side of the quote is the detail that matters most. A long position closes by selling, so its stop loss and take profit are tested against the bid. A short position closes by buying, so its levels are tested against the ask. Testing the wrong side closes positions one spread too early or too late, every time.

Worked example

A trader is short EUR/USD at 1.08500 with a stop loss at 1.08800 and a take profit at 1.08000. The stop triggers when the ask reaches 1.08800 or higher; the take profit triggers when the ask falls to 1.08000 or lower. If news pushes the ask from 1.08750 straight to 1.08900, the stop closes at 1.08900.

Modifying stops

Traders usually move stops as trades progress. Every modification should be checked against the account's rules. For example, if the firm requires a stop loss on every trade, removing it should be refused.

Why it matters for disputes

Most execution complaints concern stops: "price never reached my stop." Usually the bid or ask reached it while the mid price on another chart did not. Explaining bid and ask testing in your FAQ prevents many of these tickets.

On PropExecutor, stops and targets are tested against the side of the market the position closes on, a gap closes at the live price through the level, and stop changes pass through the order gate, so rules such as mandatory stop loss also hold when a stop is modified.