The Los Angeles Business Journal’s index of largest local public companies closed down for the week.

The weighted LABJ Stock Index fell 3 percent to 135.48 for the week ended Oct. 12. Decliners outpaced gainers 129 to 38, with 8 companies unchanged.

One of the biggest decliners was Green Dot Corp., which dropped 24 percent to $9.80. Investors in the Monrovia prepaid card provider, which gets nearly two-thirds of its revenue from cards sold at Wal-Mart Inc., were concerned by the retailer’s announcement that it was working with American Express Co. to launch a competing prepaid card.

Broadway Financial Corp. fell 17 percent to $1.28. Investors drew back from shares of the L.A. parent of Broadway Federal Bank, which the week before had jumped 28 percent after the company reported a return to quarterly profit.

THQ Inc. fell 15 percent to $3.35. The Agoura Hills video game developer was hurt by an industry report that sales of videogame software fell 18 percent last month.

Ceres Inc. lost 10 percent to $5.38. The Thousand Oaks developer of crops used for bio-fuels announced that its longtime chief scientific officer, Richard Flavell, would be leaving his operational role. Flavell will remain affiliated with the company, however, as chief scientific adviser.

Among a small handful of double digit gainers was True Religion Apparel Inc., jumping 23 points to $25.92. The Vernon designer denim maker announced that it was forming a committee to evaluate strategic options that could include a sale.

Reed’s Inc. gained 15 percent to $7.33 after the Los Angeles specialty soda maker made an online presentation to potential investors.

Guidance Software inc. rose 4.5 percent to $12.04 after the Pasadena business forensics software company showcased a new version of its legal discovery software at a trade show.