The S&P 500 was up 0.5% to 2,089.76.
The Dow Jones Industrial Average was up 0.6% to 17,950.99. The Nasdaq was up 0.6% to 4,949.28.
The yield on a 10-year Treasury bond was down 2.1% to 2.2%.
The price of gold was down 0.7% to $1,182.
Irvine-based Masimo Corp. was up 3.3% to $35.10 and a $1.9 billion market cap. After markets closed Wednesday, the device maker reported net earnings of $20.5 million in its first quarter, compared with $22.6 million in the in the same period last year; the year-ago period included about $5 million in a one-time benefit. Revenue rose to $155 million, compared with $140 million in the same period last year.
Mission Viejo-based Ensign Group Inc. was up 5.5% to $43.55 and a $1.1 billion market cap. After markets closed Wednesday, the healthcare facilities operator reported net earnings of $16 million in its first quarter, compared with $14.6 million in the same period last year, on revenue of $300 million, compared with $237.5 million last year. The company also increased revenue and net income guidance for the full year.
Aliso Viejo-based Smith Micro Software Inc. was up 9% to $1.25 and a $57 million market cap. Shares in the mobile-software maker traded at more than double the average daily volume by midday, after declining due to profit-taking. Last week, Smith Micro reported revenue growth of 25% in its first quarter, year-over-year.