The Los Angeles Business Journal’s index of largest local public companies gained following a volatile week in the larger markets.

The weighted LABJ Stock Index rose 1.3 percent to 160.79 for the trading week ended June 28. Gainers outpaced decliners 118 to 41, with six companies unchanged.

The biggest gainer was Crown Media Holdings, jumping 30 percent to $2.47. The Studio City operator of Hallmark cable channels said in a regulatory filing that Hallmark was considering taking the company private.

OSI Systems Inc. gained 15 percent to $15.32. The Hawthorne maker of scanning systems for medical and security uses said it received a large order.

Jakks Pacific Inc. rose 15 percent to $11.25. The Malibu toymaker made several new product and partnership announcements.

Puma Biotechnology Inc. rose 14 percent to $44.37. The Westwood cancer drug developer announced it was joining the Russell 3000 Index.

The biggest decliner was Demand Media Inc., falling 27 percent to $6. The Santa Monica Internet media and domain services company cut its revenue outlook for the current quarter.