Well, from what I have seen, the big day traders in Wall Street specialize in one or two instruments such as S&P 500 and use size to make their money. People are trading as much as 1000 contracts per order, they only need a liquid market.
Diversification is great for those that wish to be at their compuiter 24/7, doing research and managing, for me the simple approach is far easier....
I use very few indicators, I do not worry about curve fitting, I use only strategies that have a high win rate.
Well, regarding Mr Cleanow, perhaps he will look at EURUSD and he will notice that there is always a bit of money of the table.
Personally, I like simple, I like to make money every day and I have done my time sitting at the screen.
I am continually generating new strategies that have high acceptance requirtements, I limit the number of pairs to one. For a time i was trying to diversify and finally realized that I could do quite well with only one pair, and one time frame.
My 'secret' goal is to push EA Studio until I can net 3000 pips per day....