I think this guy was the best trader on UNG in the past few days,
his idea really won, and he was good to monitor the premium, theorically he could roll this idea in the next expiration too, was statistically winner this idea in the medium term because the premium should reduce again.
Now the problem is that the premium is still high and thousands of investors will monitor the page of UNG fund... and more will want to arbitrage.
I think some terrible day expect us and very hard strategies to think to protect our positions in UNG. Perhaps crude oil is up and the spread with gas is widen.