Exxon Mobil lost its triple-A credit rating Tuesday. If crude oil’s steep selloff has taught anything, it is that no energy company is immune from it—not even industry stalwart Exxon Mobil Corp. XOM -0.49 % The energy giant lost a badge of honor on Tuesday when it was stripped of its coveted triple-A credit rating . Standard & Poor’s cited concerns about Exxon increasing its borrowing to keep up with its capital-return program. But Exxon marches to the beat of its own drummer, announcing a day later that it would boost its quarterly dividend by 3%. Typically a footnote, the timing of the announcement was poignant. For one, it maintains Exxon’s status in the S&P 500 dividend aristocrats —the select companies that have raised dividends every year for the past 25 years. And in an environment where energy companies are battening down the hatches, a boosted dividend holds that […]