The S&P 500 rose 0.2% in midday trading to 2,570.12.
The Dow Jones Industrial Average jumped 0.9% to 23,474.91.
The Nasdaq increased 0.3% to 6,603.20.
The yield on a 10-year Treasury bond rose 1.4% to 2.41%
The price of gold fell 0.3% to $1,277.
Irvine-based ChromaDex Corp. (Nasdaq: CDXC) fell 4.1% to $4.01 and a $193 million market cap. Shares of the maker of ingredients for dietary supplements are still up about 79% from a 52-week low in April.
Peregrine Pharmaceuticals Inc. (Nasdaq: PPHM) climbed 3.7% to $4.26 and a $192 million market cap. The Tustin-based company named Patrick Walsh, chief executive of contract manufacturer Avista Pharma Solutions, to its board. Shares of Peregrine, which is developing drugs to fight cancer, have risen about 48% since Sept. 8.