Using 'or' instead of 'and', 08/20/05
Here's a simple system we'll improve using 'or' to broaden its scope instead of using the more traditional 'and' which narrows scope:
Buy on the close if the normalized MACD is < -2
Exit after two consecutive up open-to-closes
From 1997 to present in the SP futures this system was:
45/66, 68%, avg 5.3 pts, sd 24.4, z 1.8
A statisticaly significant system with stable control charts:
But with only 66 trades over 8 years there's really not enough meat for a meal so we'll use 'or' to increase the number of trades and to run a psuedo out-of-sample test on the original system.
You may have noticed that all oscillators like MACD behave similarly, so add the following parameters to the system:
Buy on the close if:
normalized MACD < -2 or
normalized Sharpe Ratio < -2 or
normalized ROC < -2 or
normalized Stock/Bond Ratio < -2
Exit after two consecutive up open-to-closes
From 1997 to present in the SP futures this system was:
83/118, 70%, avg 4.9 pts, sd 27.6, z 1.9
Again a statistically significant result with even better looking control charts:
Using 'or' improved the original system in two ways:
1) 'or' nearly doubled the number of trades and improved the design's z score
2) 'or' helped validate original concept with a pseudo out-of-sample test as the design continued to work when we added 3 baskets of related signals
Conclusion: 'or' can be applied to many system designs to increase the number of trades, improve profitability and provide additional robustness.