Stocks of hospital companies rose sharply and insurance companies fell Thursday after the Supreme Court upheld a requirement that almost all Americans carry health insurance.

The stock of Hospital Corp. of America, the largest private hospital chain in the United States, rose 8.5 percent. Quest Diagnostics rose almost 3 percent.

Insurance companies were down sharply as analysts rushed to sort out the ruling. Shares of Indianapolis-based insurer WellPoint Inc. were down more than 5 percent after the ruling was announced, to $65.51 each.

UnitedHealth Group stock fell almost 3 percent.

The broader stock market was down a little more than 1 percent.

Chief Justice John Roberts, in a break with other conservative justices on the high court, sided with the majority in allowing the law to go forward with its aim of covering more than 30 million uninsured Americans.

Stocks of the largest drug companies in the country were down but not heavily, in line with the broader market. Shares of Indianapolis-based Eli Lilly and Co. were down about 1 percent, to $41.45 each.

Stocks of medical device makers were also down about the same as the broader market.

The court found problems with the law's expansion of Medicaid, but said the expansion could proceed under certain conditions.