Yes, i believe i do based on backtesting since 2008 and also some live trading. @algofy. Thanks for bringing that point though. @Handle123 CL had a quite a bumpy ride since 2008 till now. I believe backtesting for that period gives a good confidence
What you are looking for is diversification. You mention that you intent to use the same trading strategy on each of the instruments, so that does not provide diversification. Then you can look for diversification in the instruments which you use. CL and NG are both in the energy basket and have a rather high correlation. So this will probably not help you in finding diversification. It would probably be better to look for instruments which are in completely different asset classes.
You are right.. NG and CL kind of trended similar last 10 years. I will need to find 3rd diverse instrument in addition to ES and CL which should be liquid enough
Many classes to choose from. For example: metals, equities, bonds, volatility, agriculture, forex. You could start by looking at this page: http://www.mrci.com/special/corr180.php and look for pairs that have a low correlation (i.e. their value is approximately between -20 and +20).
@autom you are welcome. Another poster at ET pointed me to it and I had the same response when I saw it.