How does MT4 get spread in backtesting?

Hi everyone. This post is somewhat relateed to my previous http://forums.babypips.com/forextown/54420-mt4-ea-backtesting-how.html. So I’m trying to backtest on MT4 offline with historical data from Dukascopy. These prices when converted and imported to MT4 history center are bid only. Now I wonder what spread will MT4 use if he doesn’t have the ask part? Will he use a constatnt spread of 2 pips for instance, or is there any other logic begind this? Thanks for you help guys.

If you check under your backtesting area and look under properties for the currency you will see the fixed swap and spread that the backtester applies to each pair.

Yup, it looks you are right, I see 2 pip spread for EURUSD, is there any way to possible change it in some settings? I know it would will still be a fixed spread, which doesn’t exist in live trading, therefore you can not count on the results from backtesting 100%, but it gives you some clues where your EA goes. IMHO, if it makes some profit, especially if the balance chart shows some kind of constant growth, then the EA may be usefull in live trading. But if your profits are like “zigzag” or you make constant losses, you better forget to use it in live trading.