Discuss which is better and why: Trade a few instruments Pros: ->Chance to develop in-depth market dynamics of one instrument very well ->Chance to develop good tape reading skills ->Chance to understand the cumulative effects of participants on that market ->You get to know intimately effect of news on that market Cons: ->Much harder to become consistent. ->Having 4 or more losing months in a year is common. ->Can't diversify risk (if you are trading index like ES, then it doesn't apply strictly) ->Your particular market can go through lean phase. How will you make money then? Trade a Large Portfolio Pros: ->Diversified risk ->Less stress since you make money almost every month ->Not dependent on a particular market's current trading conditions Cons: ->Partial/Full Automation is must ->Could lead to fat finger mistakes in Partial automation ->You tend to trade statistically. So far so good. But you never learn intricacies of a particular market ->Possibly weak intuition feeling compared to trading only a few symbols.