The Los Angeles Business Journal’s index of largest local public companies eked out a slight gain for the week ended Jan. 7, as investors reacted to disappointing jobs and retail sales reports.

The weighted LABJ index rose 0.55 percent to 119.66, with gainers outpacing decliners 98 to 77.

Among the biggest gainers was Woodland Hills-based ReachLocal Inc, which provides online advertising services to small- and medium-sized businesses. It ended the week up 30 percent to $25.53 after a flurry of trading on Monday. Analysts speculated that traders shorting the stock had been covering their positions.

MPG Office Trust Inc., a real estate investment trust and big downtown Los Angeles landlord, one rose 13.6 percent to $3.09 after a strong week for commercial REITs.

Los Angeles homebuilder KB Home gained 13.4 percent to $15.25 after reporting a better-than expected fiscal fourth quarter on Friday.

Among the biggest decliners were apparel retailers hurt by industry reports that the holiday shopping season had ended weaker than expected.

Los Angeles-based Guess Inc. dropped 11.2 percent to $20.08, and Vernon-based True Religion Apparel Inc. was down 11 percent to $20.08. City of Industry’s Hot Topic Inc., which said same-store sales last month were down less-than-expected, still saw its stock drop 6.2 percent to $6.04. Also affected was El Segundo toymaker Mattel Inc., which fell 5.5 percent to $24.18.

Cyber Defender Corp fell 11.7 percent to $2.72. The Los Angeles a provider of Internet security software made co-founder Igor Barash chief operating officer.