The S&P 500 was down 0.4% in midday trading to 2,769.96.
The Dow Jones Industrial Average fell 0.6% to 24,941.43.
The Nasdaq was off 0.2% to 7,733.20.
The yield on a 10-year Treasury bond increased 0.1% to 2.93%.
The price of gold was up 0.2% to $1,281.
Newport Beach-based Clean Energy Fuels Corp. (Nasdaq: CLNE) rose 5.9% to $3.08 and a $470 million market cap. On June 16, the Motley Fool investing website cited Clean Energy as one of three stocks “that could put Tesla’s returns to shame.” Shares of the operator of renewable natural-gas fueling stations have more than doubled since a 52-week low in March.
Costa Mesa-based Veritone Inc. (Nasdaq: VERI) climbed 2.2% to $23.56 and a $385 million market cap. Shares of the company, which has an online ad-placement business and is trying to expand into artificial intelligence, have climbed 79% since April 5, when it announced a new version of its artificial-intelligence operating system.