The S&P 500 was up 0.7% to 2,121.21 in midday trading.
The Dow Jones Industrial Average was up 0.2% to 18,093.96.
The Nasdaq was up 1% to 5,149.06.
The yield on a 10-year Treasury bond was up 0.2% to 2.35%.
The price of gold was down 0.3% to $1,144.
Irvine-based Masimo Corp. was down 1% to $38.30 and a $2 billion market cap. BTIG Research downgraded the medical device maker’s shares to “neutral.” The share price is up 49% year-to-date.
Costa Mesa-based Nemus Bioscience Inc. was down 23% to $1.20 and a $20 million market cap on high volume. The medical marijuana products developer had by midday traded about five times as many shares as in its 90-day full-day average.