The S&P 500 fell 1.26% to 1,864.70 in afternoon trading Thursday.
The Dow Jones Industrial Average was down 1.25% to 16,406.43, while the Nasdaq was off 1.27% to 4,048.47.
The yield on a 10-year Treasury bond fell 1.77% to 2.50%.
The price of gold slipped 0.92% to $1,293.90 per ounce.
HEALTHCARE
Foothill Ranch-based nursing home operator Skilled Healthcare Group Inc. rose about 11% to $5.81 for a market value of $230.13 million. The gain followed news that competitor Kindred Healthcare Inc. in Louisville, Ky., is making a hostile, $533 million bid for Gentiva.
REAL ESTATE
The National Association of Home Builders said its homebuilder confidence reading fell in May, sending homebuilders shares down.
Newport Beach-based William Lyon Homes fell about 3% to $26.36 for a market value of $823.01 million.
Irvine-based TRI Pointe Homes Inc. slipped about 2% to $16.19 for a market value of $512.12 million.
CLEAN TECHNOLOGY
Newport Beach-based Clean Energy Fuels Corp. was off about 3% to $9.72 for a market value of $873.42 million.