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

The weighted LABJ Stock Index closed down 0.2 percent to 170.51 for the trading week ended September 27. Decliners outpaced gainers 84 to 76, with five companies unchanged.

One of biggest movers was again Virtual Piggy Inc., dropping another 23 percent to $1.17. The Hermosa Beach provider of online financial products for families has been dragged down by negative articles about the company’s founders and financial backers.

CytRx Corp. jumped 36 percent to $3.38. The Los Angeles cancer drug developer benefited from an investor conference presentation earlier this week.

Arrowhead Research Corp. rose 27 percent to $6.05 The Pasadena drug developer benefited from some positive media coverage.

Motorcar Parts of America Inc. rose 22 percent to $12.66. An analyst initiating coverage on the company gave the Torrance auto parts maker’s stock a “buy” recommendation.