The Los Angeles Business Journal’s index of largest local public companies closed up for the week ended Dec. 30 as investors locked in their year-end portfolios.

The weighted LABJ index rose 1.03 percent to 119.01, with decliners outpacing gainers 91 to 88.

La Canada Flintridge sporting goods chain Sport Chalet Inc. soared 32 percent to $3.65, as the retail sector benefited from reports of a solid holiday shopping season in certain sectors.

RadNet Inc. rose 7.6 percent to $2.96. The Los Angeles operator of outpatient diagnostic imaging centers nationwide last week announced acquisition of a New York company that provides remote interpretation of diagnostic imaging exams to health care providers.

Other companies also saw double-digit gains despite a lack of market-moving news. Woodland Hills small-business online advertising agency ReachLocal Inc. jumped 13 percent to $19.60. Covina bank holding company Kaiser Federal Financial Group Inc. gained 10 percent to $11.56.

Among the decliners was Los Angeles Internet security software provider CyberDefender Corp., which last week announced it had regained compliance with Nasdaq listing requirements. Shares were down 6 percent to $3.08.

Homebuilders continued to be hurt by last week’s news that November new-home sales were less than half the level that economists consider healthy. KB Home in Westwood fell 5 percent to $13.45 and Ryland Group Inc. in Calabasas was down 4 percent to $17.09.