If you want to play Natural Gas, why not play futures instead. There's no BS indefinite short selling like you see on these ETF/ETNS
/NGH4 is the best and safest bet. I wouldn't touch these ETF/ETN's as they're all designed to end up at $0 when they start them at $100+ like this.
If anything sell options against it. Natty Gas going to $7 by mid December is my guess. Have fun buddy
(Yeah, because this is soooooo 'off-topic' haha.. come on 'admins', get real)