Principle 14:
Variance reduction appears in two examples in trading:
1. Number of bars you work with.
2. Your gains and returns.
With respect to 1. Go back to the time trading system. You need to make sure that X is at least 20 bars.
If you do not do that, you wins and losses out of X will not help you to decide.
Variance reduction is also and important component in money management, but usually this part is taken care of implicitely is your rule is to make sure you survive in 20 or more trial.
Notice the number 20 in there and its relation to central limit theorem. 20 corresponds to 5% losses. If you used more than 5% loss on a single trade, then you are not controlling variance as you should. Do not use courage in money management by thinking that a higher number applies to you. It has nothing to do with courage but rather numbers.
Variance reduction appears in two examples in trading:
1. Number of bars you work with.
2. Your gains and returns.
With respect to 1. Go back to the time trading system. You need to make sure that X is at least 20 bars.
If you do not do that, you wins and losses out of X will not help you to decide.
Variance reduction is also and important component in money management, but usually this part is taken care of implicitely is your rule is to make sure you survive in 20 or more trial.
Notice the number 20 in there and its relation to central limit theorem. 20 corresponds to 5% losses. If you used more than 5% loss on a single trade, then you are not controlling variance as you should. Do not use courage in money management by thinking that a higher number applies to you. It has nothing to do with courage but rather numbers.