The Nasdaq was down 2.26% to 2,944 in midday trading Wednesday, while the Dow Jones Industrial Average was off 2.09% to 12,968.
The S&P 500 fell 2.04% to 1,399.
The yield on a 10-year treasury bond was down 5.91% to 1.64%.
The price of gold was off 0.13% to $1,717 per ounce.
Clean Energy Fuels Corp. fell about 7% to $11. The drop gave back stock gains marked Tuesday, when the Seal Beach-based company posted better-than-expected third-quarter revenue. Clean Energy had a recent market value of $977 million.
Aliso Viejo-based Microsemi Corp. fell about 6% to $19 for a market value of $1.7 billion. Chipmakers were generally down on Wednesday.
Shares of Aliso Viejo-based networking-equipment maker QLogic Corp. fell about 5% to $9 for a market value of $859 million.
Irvine-based laser maker Newport Corp. was off 5% to $12 for a market value of $466 million.