A demo account is valuable for checking installation, signals and broker compatibility, but it is not a perfect model of live execution. The important question is not whether every result matches; it is whether the difference can be explained, measured and kept within the strategy’s risk limits.
Why Demo and Live trades diverge
| Factor | Demo environment | Possible Live effect |
|---|---|---|
| Spread | Often smoother or simulated. | Can widen at rollover, news or low liquidity. |
| Slippage | Fills may be simplified. | Requested and executed prices can differ. |
| Liquidity | No real market impact. | Large or fast orders can receive partial or different fills. |
| Commission and swap | May use different account conditions. | Changes net result and overnight cost. |
| Latency | Server route may differ. | Signals reach the trade server later. |
| Trading rules | Demo settings can be more permissive. | Stops Level, volume or order limits may differ. |
Compare behaviour before comparing profit
Start with timestamps, symbols, direction, lot size and order comments. If both accounts receive the same signal but fill at different prices, investigate execution. If one account never generates the signal, investigate quote history, spread filters, terminal time, EA settings or licensing.
Diagnose differences in the right order
Verify the setup
Confirm AutoTrading, the chart symbol and timeframe, the smiley status, DLL permissions if required and the licensed account number. A configuration mismatch is more common than a strategy defect.
Compare the incoming market conditions
Record Bid, Ask, spread and broker server time around the expected entry. An EA with a maximum-spread filter can correctly skip a trade that appears on another account.
Read the order result
Check the Experts and Journal tabs for invalid volume, invalid stops, off quotes, requotes, insufficient margin or disabled trading. These messages identify the layer that rejected the action.
Compare enough trades
One fill is not a representative sample. Compare a series of trades across the strategy’s normal sessions and include commissions, swaps and closed as well as open positions.
Move from Demo to Live with controlled risk
Keep the configuration fixed during the comparison. Begin with a position size that makes an unexpected fill or short drawdown financially tolerable. Do not increase risk merely because a short demo period was profitable. Monitor connection uptime, free margin and log errors on the VPS, and pause the EA if execution repeatedly falls outside the planned conditions.
Real funds introduce execution, liquidity and emotional consequences that a simulated balance cannot reproduce.
Set realistic expectations
Small differences in entry price and net profit are normal. Persistent missing trades, opposite directions, repeated server errors or materially different position sizes are not. The objective is to establish whether discrepancies come from setup, data, broker rules or execution before changing the strategy itself.
Official reference
The official MQL4 OrderSend reference documents requested price, slippage, stop levels and server errors that can affect live order execution.