They’ve also invested heavily in Republican politics, including support for President Donald Trump. In 2016, the Wilkses set up a super-PAC with $15 million of their own money to support the presidential campaign of U.S. Senator Ted Cruz. This year, they each contributed $50,000 to the Trump Victory PAC and $44,400 to the Republican National Committee, according to Federal Election Commission records.

Church Leader

Farris Wilks was the long-time leader of the Assembly of Yahweh, a nondenominational church outside of Fort Worth that was founded by his grandfather. Its congregants observe the Sabbath on Saturday and adhere to kosher dietary rules. Farris has preached against homosexuality and abortion, according to a 2015 Reuters report. As for climate change, he told congregants in a 2013 sermon that it’s God’s will.

Even after the oil-market crash of 2014-2016, the brothers continued to invest in Permian Basin explorers and related industries such as companies that supply sand and other materials used in fracking the region’s vast shale formations.

Although oil prices have rebounded since, they haven’t fully recovered as an overabundance of crude has overwhelmed local pipeline capacity, gutting profits and cash flows.

Things were even worse for companies with wells that produced a lot of natural gas: a massive oversupply of the fuel forced some West Texas drillers to choose between shutting down production or accepting negative pricing -- effectively paying someone else to take their gas.

The Wilkses’ post-crash investment optimism has proven to be misplaced.

Carbo Ceramics Inc., the Houston-based frack-sand supplier that counts the duo as it’s second-biggest investor, warned this month that it may fail as a going concern after its biggest customer halted purchases. The stock has plunged 72% since the Nov. 8 announcement.

Carbo and other oilfield-services companies are seeing demand evaporate as explorers rein in spending to mollify investors insisting they prioritize shareholder returns over production growth.

Still, the brothers do have at least one big advantage, said Neal Dingmann, an analyst at SunTrust Robinson Humphrey.