Just like Sunday open week ago, last night large order on the open (about 250 contracts) sold to very thin market. Under all normal conditions, you'd just buy and enjoy 4-7 cents easy pullback. But there is no reason to buy this great commodity without weather and storms. Storage is full, they started filling it up little late this season, but now very well above 5-year average with production/demand beeing at same levels. Want to know what can happen? Look at Oct 06 contract. It expired at the very low of it's life - $4.195. Yeah, I know, Amaranth added to unusual moves.
I must say, however, I've been long myself, I also have been selling calls to protect my account. Sold sep 5.30 calls today at 10 cents when natty was at 5.25, they expire tomorrow.