The Los Angeles Business Journal’s index of largest local public companies gained for the week as investors reacted to positive economic news and earnings reports.

The weighted LABJ Stock Index closed up 2 percent to 144.76 for the trading week ending Feb. 1. Gainers outpaced decliners 111 to 54, with six companies unchanged.

The biggest gainer was Trio-Tech International, which jumped 24 percent to $2.25. The Van Nuys maker of semiconductor test equipment reported an 11 percent increase in revenue for its fiscal first quarter.

Several companies also saw double-digit percentage gains despite a lack of market-moving news. Hermosa Beach e-commerce company Virtual Piggy Inc. rose 16 percent to $1.16. Los Angeles specialty soda maker Reeds Inc. gained 16 percent to $5.95, and Los Angeles apparel company American Apparel Inc. added 12 percent to $1.41.

The biggest decliner was Herbalife Ltd., falling 19 percent to $25.07. The L.A. nutritional supplement company’s stock continues to be volatile ahead of its fourth quarter earnings report as some high profile hedge fund traders continue to debate the merits of the company’s multi-level marketing business model.