The S&P 500 rose 0.23% to 1,659.26 in afternoon trading Wednesday.
The Dow Jones Industrial Average was up 0.38% to 14,832.17, while the Nasdaq was off 0.33% to 3,682.72.
The yield on a 10-year Treasury bond rose 1.10% to 2.66%.
The price of gold slipped 1.34% to $1,306.90 per ounce.
Anaheim-based action-sports retailer Pacific Sunwear of California Inc. shares were off about 8% to $2.77, after Piper Jaffray Cos. lowered its rating on the company's stock from "overweight" to "neutral.” Pacific Sunwear had a recent market value of $189.86 million.
Newport Beach-based Alliance HealthCare Services Inc. was down about 8% to $26.95. New York investment ratings agency Moody's Investors Service lowered the rating on Alliance's senior secured credit facilities from "Ba3" to "B1." Moody's also lowered its default rating on Alliance from "B1-PD" to "B2-PD." Alliance had a recent market value of $279.93 million.
Newport Beach-based Clean Energy Fuels Corp. shares continued to fall, down about 3% to $10.99 for a market value of $981.79 million. The company closed down about 9% on Tuesday after Piper Jaffray reiterated its "sell" rating on the company's stock, and said that trucking companies generally prefer cheaper compressed natural gas to the liquefied natural gas that Clean Energy handles.