Spread in Strategy Tester

 
How do you change the spread? I assumed it was under Symbol Properties, but the field is read only. It appears to use a 0 spread when you backtest.

Thanks,
Bryant Ingram
 
 
Actually, I saw that already and assumed there was a more practical way to change the spread. Obviously, you expected a better answer as well.
 
i'd like to change the spread for particular ticks only

for all of test data you can change it in this way "struct TestHistory in fxt"