MQL5 Checks for Sessions, Margin, Trade Risk, and New Bars
Summary
This practical MQL5 guide describes checks that can help an Expert Advisor respect trading conditions and account constraints. It shows how to enumerate trading and quotation sessions, estimate required margin for market or pending orders, and calculate the potential profit or loss between an entry price and a stop level. It also explains detecting a newly opened bar so a strategy can limit signal evaluation or trade actions to once per bar.
The examples illustrate platform functions and validation routines, including checking that trade volume falls within a symbol’s minimum, maximum, and step. The article notes that pending-order margin requirements depend on broker or symbol settings, and that a tester’s open-prices-only mode can handle once-per-bar execution during testing. These are foundational checks rather than an exhaustive account of operational safeguards. The text does not provide comparative strategy results, and live systems still need checks suited to their account and instrument conditions.
Key ideas
- Session functions can enumerate trading and quotation periods by weekday and session index.
- OrderCalcMargin estimates margin for an order type, volume, symbol, and price, including pending orders.
- OrderCalcProfit can estimate the monetary outcome between entry and exit prices for a buy or sell position.
- Comparing the current bar’s opening time with a stored time provides a way to detect a new bar.
- Volume validation should account for the symbol’s minimum, maximum, and permitted increment.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.