Dylan Martinez Livepic | Reuters
The S&P 500's health care sector fell Thursday after a federal judge ruled the Obama administration is unconstitutionally spending federal money to fund Obamacare.
Shares of UnitedHealth Group and Endo International fell more than half a percent, while Aetna, Cigna, and Humana fell more than 1percent.
The ruling Thursday from U.S. District Judge Rosemary Collyer is a win for House Republicans who brought the politically charged legal challenge.
At stake is $175 billion the government is paying to reimburse health insurers over a decade to reduce co-payments for lower-income people.
— The Associated Press contributed to this report.