If higher demand failed to materialize, oil inventories could build up, causing prices to plunge.

By selling futures, in other words, a company would have effectively sold out all its crude oil inventory.

A year ago, domestic crude oil inventories totaled 343.7 million barrels.

The rise was spurred by an increase in crude oil inventories that was less than expected.

The decline occurred despite a report that the nation's oil inventories were falling.

To be sure, nobody really knows the state of oil inventories.

The winter has drawn down our heavy oil inventories more than usual.

In recent weeks oil inventories held by consuming nations fell sharply.

Nobody is predicting serious shortages; oil inventories are neither especially high, nor extremely low.

Higher crude oil inventories also put pressure on prices.