The traders are simply taking profits. They want to lock-in their gains before the inventory report comes out on Wednesday.
In the past few weeks, right before the announcement of the inventory report the market generally comes down.
Gasoline inventories in the U.S. continue to be an issue in the market because last week's inventory report showed a stock decline as we approach the summer driving season.
The market expects the DoE report to show a build up of US inventories across the board.
This morning the market is continuing its momentum ... from the response to the inventory report from the US.