The stock rallied strongly because Hovensa has been a black hole, losing $1.3B in the past three years. The older portion of the refinery was closed in Jan 2010 (#msg-59363574).
HES will take a $525M after-tax charge against earnings in 4Q11; the PR does not specify the proportion of the write-off that is a cash expense, but I suspect that most of it is a non-cash adjustment to the carrying value on the balance sheet.
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”