Of the 1000 largest U.S. companies, the biggest winner of the election was Corrections Corporation of America (CXW), one of the nation’s largest operators of private prisons. Corrections Corp. stock soared more than 49% by the early afternoon, while another private-prison stock GEO Group (GEO) surged more than 21%.

Together, those gains added more than $1 billion to the market values of the prison companies. The Dow Jones Industrial Average and S&P 500, meanwhile, inched up less than 1% each, bucking predictions that Trump’s victory would cause a market crash of epic proportions.

The prison stocks weren’t simply reacting to Trump’s win, but Clinton’s loss. In her campaign for the White House, Clinton had taken aim at for-profit prison corporations, pledging not just safety reforms, but to put them out of business altogether. Announcing her anti-private prison stance on Twitter last year, Clinton sent Corrections Corp. of America stock tumbling 6%, while GEO Group shares fell more than 4%.

"We need to end private prisons. Protecting public safety…should never be outsourced or left to unaccountable corporations." —Hillary

— Hillary Clinton (@HillaryClinton) October 30, 2015

Since then, private prison stocks had traded at depressed prices, sometimes valued at less than 10 times earnings. Further hurting the stocks, the Justice Department said in August that it would stop using private prisons, and urged other government agencies to do the same, citing unsafe conditions. Yet it’s unclear whether a Trump administration will follow through on that directive,

Trump endorsed private prisons in March, telling MSNBC’s Chris Matthews, “I do think we can do a lot of privatizations and private prisons. It seems to work a lot better.”

The president-elect’s hardline attitudes towards illegal immigration and crime may also lead to more incarceration, which could benefit private prison companies.