LOL, futures will get raped by pure Bitcoin markets. While they are closed for the night/weekend/giftmas... Bitcoin exchanges truck on, and when it moves 10 or 20% during that time, futures will open with gaps and those on the wrong side will be ruined with losses and possibly owing above their account values. This will be great 
CME futures only closed for 60 minutes per day, except closed weekends.
Don't you think traders will close positions before the weekend or appropriately hedge across that gap every weekend?
Also don’t you think the margin requirements will be appropriately computed on the high history of volatility of BTC?
You seem to presume these folks can’t do math.
But maybe you’re correct, that the margin requirements for safety are too high for most to play. However, if margin is provided in BTC that would be less onerous, e.g. miners hedging.
http://cfe.cboe.com/cfe-products/xbt-cboe-bitcoin-futures/contract-specifications
This is the one that opened today. It has extended hours, but those sessions aren't available to everyone. Normal hours are 8:30am-3:15PM Monday-Friday.
It might be marginally safer than I first expected but then again, I'm pretty sure I heard they allow 20x. If that is the case, it is definitely too high for a lot of traders to handle, hence why places like BFX only has 2.5x. Still a lot can happen during the times they are closed and I wouldn't put it past those that can, gaming it from both sides. It'll still be interesting to see how things go until it matures.
