Hess was the best-performing oil stock in the S&P 500 through the first half of the year. Several factors fueled its high-octane gains. For starters, the company and its partners ExxonMobil ( XOM 0.80% ) and China's CNOOC continued finding more oil offshore Guyana. By the end of 2018, the Exxon-led partnership had made 10 discoveries that contain an estimated 5 billion barrels of oil. In addition to that, Hess continued shoring up its financial position by selling its operations in the Utica Shale, which, when combined with asset sales from prior years, gave the company the cash to retire debt, buy back stock, and prefund its share of the first phase of development in Guyana. Add to that the company's return to growth in the Bakken and the boost from higher oil prices for much of the year, and Hess finally returned to profitability during the third quarter.