<i>"Emini S&P Midcap 400 is the only one that moves like the ER2 and gives the same bang for buck. But volume is around 30 thousand a day compared to ER2 300 thousand a day. You'll have to hope everyone jumps on it come August.</i>
When I started trading ER2 back in 2004, I believe the usual daily volume was something like 50k ~ 60k contracts. It made straighter, bigger moves more often back then... before the endless stream of fade-traders began taking turns losing their accounts trying to buck every directional move.
ER2 still makes significant $$ moves every day, just a bit more erratic now than before.
At this moment in time, EMD is suitable for one to two contracts max. It very often slips one tick on even a single contract, and jumps over limit orders regularly. Not exactly trader friendly in all aspects right now. Remains to be seen what happens ahead, any changes will come at the last minute if/when some ER traders are forced to switch.
As for the cost of data feed? $2 fee to access ICE is irrelevant. Those little costs of doing business as a trader aren't even an afterthought. Honing various trader management skills to maximize profits kept at day's end are the sole focus of importance. Fixed costs are a red herring, the wrong rabbit trail if you'll pardon the mixed metaphors.