Quote from NoDoji:P.S. - CL and 6E are much easier to trade for a living with 1 contract than ES. But they require very strict risk management.
I agree with that 150%... and one needs to define the term, "trade for a living" to some standard of measure...
The median annual income is $30+K as profiled here: http://en.wikipedia.org/wiki/Median_household_income
So with that as some sort of basis to work from, it would take +300 cents CL or +240 pips 6E or +300 pips EURUSD, GBPUSD (etc) or +30 index points TF or +60 points ES monthly to make +$3,000 calendar month gross, before all trade costs involved.
That is pure math on its face. Of those choices above, I'd rate ES as (by far) most difficult to accomplish due to its congestive, choppy nature and then CL due to its wildness nature.
The ES offers least potential price range opportunity, CL offers ample potential opportunity but frequently blows thru stops for slippage AND blows away from targeted entry-point fills (on winners) without ability to execute.
Remaining symbols are a matter of personal choice. They all have their own bad-hair days and warts. TF offers the greatest reward/risk parameters in price movement for all eminis. 6E is much more methodical than CL, albeit more muted too.
FX pairs are perfectly fine with any reputable FX broker... no broker-dealer trades against anyone's 1-lot or even 2-lot to 5-lot FX positions. FX brokers with dealer desks trade against their collective book positions, blended. They cannot trade against thousands of open positions individually... nor would they need to.
Trading against the collective sum of all open positiions is the same end result. So any individual FX spot trader with a couple of contracts on thru reputable brokers only needs to worry about overall markets and news events... no one is hunting individual stops.
All that said, I don't know why anyone would need to try and make a living with one contract of anything. If you're profitable with one, then two or three or five of whatever is no further stretch to accomplish.