Quote from BigBubba:
as i fwd test, (which to me would be a month or 2 for verification), i create new signals, new systems. i think i have some good ones. i'm afraid i'll have a hard decision deciding which system to go live with. in another month, i'll have 50 more systems.
do you have a suggestion?
maybe i should stop making systems.
lol
There are always good reasons to explain why a system might work or fail. However, there are effects that are not predictable even with the best models and theories (e.g., dip buyers). In that case, it takes common sense and trading acumen to decipher between anomaly and "real" causality.
My point is: Testing in sample/out of sample data is meaningless if the underlying principle can't explain the effect in the first place.
Once your family of systems passes that test, this is basically how I choose alerts generated from several dozen systems:
- Define the acceptable profit target and max drawdown
- Forecast future mean return and standard deviation (ARIMA methods, etc)
- Portfolio optimization to determine best mix of systems with same return but less risk
- Repair/rebalancing (ideally in real-time, if you know how)
Most importantly, you must use log returns in your analysis ( log(p2/p1) )