The S&P 500 was down 0.1% in midday trading to 2,137.84.
The Dow Jones Industrial Average was flat at 18,202.93.
The NASDAQ was down 0.4% to 5,231.81.
The yield on a 10-year Treasury bond rose 3.2% to 1.85%.
The price of gold rose 0.3% to $1,270.
Irvine-based Western Digital Corp. was up 6% to $60.39 and a $17 billion market cap. The memory products maker reported quarterly results that beat analyst estimates.
Costa Mesa-based TTM Technologies Inc. was up 18% to $13.39 and a $1.3 billion market cap. The printed circuit board maker earned $26 million on revenue of $642 million in its most recent quarter; it posted a loss for the same period last year on slightly higher revenue of $652 million.
Irvine-based TRI Pointe Group Inc. was down 6.5% to $11.22 and a $1.8 billion market cap. The homebuilder earned $35 million on revenue of $579 million. Revenue beat expectations; income missed.
Irvine-based Quality Systems Inc. was up 7% to $12.36 and a $760 million market cap. The medical practice management software maker earned $4 million on revenue of $127 million. Revenue beat analyst estimates.
Irvine-based Boot Barn Holdings Inc. was up 12.6% to $12.39 and a $330 million market cap. The western wear retailer earned $500,000 on net sales of $134 million in its most recent quarter, compared with a loss of $3.3 million on sales of $130 million in the same period year-over-year.