Hospital, health insurer stocks tumble

Hospital and health insurance company stocks were down at Friday's market close, both for the day and week as the stock market at large saw a drop.

Community Health Systems and Tenet Healthcare Corp. were hit hardest among the publicly traded hospital chains, with CHS falling 4.56% at Friday's close, and with Tenet falling 4% on a day when tensions grew greater between the company and its largest shareholder, Glenview Capital Management. Even the sector leader HCA Healthcare was down 2.49%, more than the drop in the S&P 500 index, which fell 2.12%.

The news that Amazon, Berkshire Hathaway and JPMorgan Chase were collaborating on reducing healthcare costs hit insurers hard on Monday, and after bouncing higher for a couple days, the stocks are back down to Monday's lows.

Market leader UnitedHealth Group fell 1.42% on Friday and is down more than 6% for the week. Aetna, which released mixed financial results on Jan. 30 fell a lesser 1.28% on Friday and fell 4.19% this week.