The S&P 500 was up 0.5% in midday trading to 2,650.84.

The Dow Jones Industrial Average rose 0.4% to 24,302.62.

The Nasdaq climbed 0.6% to 6,853.64.

The yield on a 10-year Treasury bond ticked up 0.1% to 2.38%.

The price of gold dropped 0.3% to $1,249.

HEALTHCARE

ChromaDex Corp. (Nasdaq: CDXC) in Irvine was up 10% to $6.89 and a $371 million market cap. The maker of nutritional ingredients reported positive results from a study of its main product’s effects on Alzheimer’s.

SERVICES

ShiftPixy Inc. (Nasdaq: PIXY) in Irvine was down 3% to $2.06 and a $59 million market cap. The company provides shift workers to restaurants via a smart app; shares are down 25% since it told the SEC it was late in filing its annual report. Last month it hired ICR Inc., a prominent investor relations firm, to provide financial and corporate communication. Shares are down by two-thirds since its June 30 IPO.

AGRICULTURE

Terra Tech Corp. (OTC: TRTC) in Irvine was up 5% to 24 cents and a $214 million market cap on high volume. The company makes hydroponic growing equipment, traditional produce and cannabis-oriented herbs.

GreenGro Technologies Inc. (OTC: GRNH) in Westminster was up 4.6% to 4 cents and a $15 million market cap on high volume. The company makes vertical cultivation systems and related products.

Sipp Industries Inc. (OTC: SIPC) in Costa Mesa was up 13% to 23 cents and a $14 million market cap. The company makes lighting products for horticulture and plans to introduce a brown ale made with hemp.