No need to get defensive ST, I'm just adding a bit of friendly discussion.
Do you mean the SSFs of the DOW 30 stocks? It seems to me that volume is too light on these contracts to really give us very useful information. I would have though YM premarket volume would be more reliable. ES is good because the DOW 30 is a subset of the S&P 500 and YM almost always moves in tandem with ES. ES volume is much higher so probably more reliable (no one trader could cause an abnormal volume spike on ES, unlike YM or SSFs).