Hello!

I was wondering what you guys consider the minimum expectancy you'd have to find in a system or methodology before you would trade it. For instance, I've tested some systems that have a very small expectancy, but worth trading? No due to comms and slippage etc. What do you guys think?

solom113 

Hello! No due to comms and slippage etc.

Could you clarify whether or not you included commissions and slippage?

If your thinking in terms of expectancy, i think it helps alot to become familiar with expected value in a more general sense.
chrisperruna.com Blog Archive What is EV or Expected Value
Expected value - Wikipedia, the free encyclopedia

You can make an arguement that you should take every trade that has positive expected value as long as it fits within a good risk management strategy.