The S&P 500 was down 0.4% in midday trading to 2,056.71.
The Dow Jones Industrial Average was down 0.2% to 17,667.80.
The NASDAQ was down 1% to 4,713.15.
The yield on a 10-year Treasury bond was up 1.3% to 1.76%.
The price of gold was down 0.3% to $1,271.
Mission Viejo-based Ensign Group Inc. was down 9% to $20.30 and $1 billion market cap. Wells Fargo downgraded shares of the healthcare facility operator to “market perform” from “outperform.”
Irvine-based ChromaDex Corp. was up 4% to $4.89 and a $178 million market cap. The ingredients maker reported net income of $255,000 on net sales of $7.3 million in its most recent quarter, reversing a $1 million net loss on net sales of $5.3 million in the same period last year.
Lombard Medical Group was down 2.6% to $1.53 and a $31 million market cap. The device maker reported a net loss on lower revenue in its most recent quarter.