Well, at least you are honest in saying you dont know if a relationship exists as you havent watched the mkts in realtime using PV. Unlike this Joe Doaks buffoon who opens his trap about how it doesnt exist and tries to use "surrogates" like the cash mkts when the method says NOTHING about those but you MUST use futures. Geez JoeD, get a clue 

Quote from Thunderdog:
Interesting. Personally, I did not think that such a relationship was likely. Admittedly, I have not tested the relationship empirically because it makes little logical sense to me. If we are to accept that one index reliably leads another by a few minutes or so, irrespective of market circumstances, then we must accept the premise that all of the arbitrageurs in all the world are reliably asleep at the wheel during this period. That presumption is rather tenuous at best. I suppose that some people may indeed have leading indicators of some kind or other, but I suspect that they would fail to lead once word got out. Since YM and ES are out there for all the world to see and compare (i.e., there is nothing "proprietary" in the comparison), I think it is counterintuitive to expect such a public goose to lay eggs on cue.