The S&P 500 was up 0.8% in midday trading to 2,897.25.
The Dow Jones Industrial Average was up 1% to 26,043.76.
The Nasdaq was up 0.9% to 8,013.85.
The yield on a 10-year Treasury bond declined 0.2% to 2.84%.
The price of gold was 0.2% higher to $1,216.
Boot Barn Holdings Inc. (NYSE: BOOT) in Irvine climbed 4.2% to $27.79 and a $778 million market cap. Shares of the retail store chain have more than tripled in the past year on growing sales.
Lantronix Inc. (Nasdaq: LTRX) in Irvine jumped 9.1% to $6.31 and a $115 million market cap. Shares have more than doubled this month as the company reported a positive fourth quarter. Furthermore, it was added the LD Micro Index and activist investor Peterson Capital announced a stake.