I have noticed on several occasions that the price of UNG will lead the price of NG futures. This has me wondering if the NG futures market is thin enough that the big players could trade UNG (less leverage) with the intent of impacting NG futures. There could be another reason or no reason at all, but I am interested in any thoughts others have on this. I posted this under energy futures because I believe the futures traders would have more insight on this that ETF traders.