It’s been a bad few years for investors in shale companies, but a pretty good few years for shale company CEOs.

The leaders of U.S. shale companies received some of the largest executive pay increases in corporate America, even as their shareholders lost billions of dollars, a Wall Street Journal analysis has found.

The median pay for chief executives of large U.S. oil and gas drillers rose for four straight years, hitting $13 million in 2019. That was up from about $9.9 million in 2015, a stretch when the companies’ median total returns to shareholders fell 35%, according to the WSJ analysis of executive compensation data from firm Equilar Inc. and returns figures compiled by Evercore ISI. Taken as a group, the shale CEOs received larger raises in 2019 than peers in all but two of the 11 major industries Equilar analyzes.

Shale companies used hydraulic fracturing and horizontal drilling techniques to unlock a gusher over the past decade, making the U.S. the world’s leading oil producer. But most have struggled to make money. Funded with a wave of Wall Street capital that began flowing in earnest a decade ago, they focused on growth over profit. Journal articles in 2016 showed that the executive bonus formulas used by many shale companies to compensate CEOs rewarded them handsomely for pumping more, regardless of whether they made money.