Chevron is on the verge of buying oil company Hess. But as Chevron waits to swallow its rival, it is snacking on Hess shares—at a discount to the implied acquisition price. Chevron revealed the purchase of 4.

Chevron bought 15.38 million shares of Hess' common stock via the open market, even as the companies work to complete their embattled merger.

Chevron bought about 4.99% of Hess Corp's common shares this year, reflecting its confidence in completing the planned acquisition of Hess, the oil giant said in a regulatory filing on Monday.The second-largest U.