Quote from kxvid:
I don't know but it would be bad if ETFC failed. All that 1000 new accounts a day talk, that would be a nightmare for the SIPC.
My understanding is just because something isn't covered doesn't mean the SIPC won't work to sort it out. People with futures positions have gotten their positions back after a brokerage failure even though they aren't covered.
The funds in a futures account are usually held in a segregated account, which means that if the broker fails then your funds are safe.