UnitedHealth Group saw shares fall 11.5 percent in December, the same month a federal judge struck down the ACA, according to The Motley Fool.
On Dec. 14, U.S. District Judge Reed O'Connor ruled in favor of a lawsuit filed by 20 states claiming the ACA's individual mandate became unconstitutional when the 2017 tax law eliminated the associated penalty. The mandate is inseverable from the rest of the law, making the ACA unconstitutional, according to the lawsuit. Seventeen states have appealed the decision.
The decision likely had a negative effect on the shares of UnitedHealth. Investors sliced $31 billion from the health insurer's market cap in December, according to the report.
The health insurer serves 6.6 million Medicaid beneficiaries and nearly 495,000 members with coverage through the ACA exchanges, according to the report.
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