The S&P 500 was up 0.9% in midday trading to 2,090.03.
The Dow Jones Industrial Average was up 1% to 17,865.49.
The NASDAQ was up 0.8% to 4,818.37.
The yield on a 10-year Treasury bond was up 1% to 1.49%.
The price of gold was down 0.4% to $1,321.
Costa Mesa-based TTM Technologies Inc. was up 5.1% to $7.40 and a $741.2 million market cap on high volume. The printed circuit board maker had by midday traded shares at a rate three times its 90-day average.
Anaheim-based Eaco Corp. was up 12% to $5.68 and a $27.6 million market cap. The electronics parts maker said in the quarter ended May 31 net sales grew 8.1% year-over-year to about $40 million and net income increased 38% to $1.6 million.