Tweaking a trading system - How much data?

[wino59]

Okay here is the deal... I have a trading system I have been using the last month.

I am trading stocks on price action, usually hit or miss within 1 to 3 days.

So far 21 trades, 17 wins and 4 losses... 81% win percent.

I went back on the 4 losses, and if I would have double the exit number of shares, they all would have hit the target in the opposite direction.

So my question is how many trades do I consider it to be viable? So far I haven't played the "false breakouts" but if they keep hitting the opposite direction I think there is no reason not to start playing them.

I am just wondering how many of them I should track to get a hit percentage, before I start playing them. Right now the hit percent is 100%, but that is only on 4 trades, so I am wondering about the accuracy.

Thoughts?

 

[ast4]

Okay here is the deal... I have a trading system I have been using the last month.

I am trading stocks on price action, usually hit or miss within 1 to 3 days.

So far 21 trades, 17 wins and 4 losses... 81% win percent.

I went back on the 4 losses, and if I would have double the exit number of shares, they all would have hit the target in the opposite direction.

So my question is how many trades do I consider it to be viable? So far I haven't played the "false breakouts" but if they keep hitting the opposite direction I think there is no reason not to start playing them.

I am just wondering how many of them I should track to get a hit percentage, before I start playing them. Right now the hit percent is 100%, but that is only on 4 trades, so I am wondering about the accuracy.

Thoughts?

Why don't you backtest against 10 years? Also stress test against major historical events (e.g. lehman, 9/11).

As a side note, win rate doesn't mean much without gain/loss per trade.