The Los Angeles Business Journal’s index of largest local public companies made gains at the end of a shortened trading week on Thursday, ahead of the markets’ close on Good Friday.

The weighted LABJ Stock Index closed up 2.8 percent to 181.97 for the trading week ended April 17. Gainers outpaced decliners 78 to 73, with nine companies unchanged.

The biggest gainer was Jakks Pacific Inc., which rose 19 percent to $8.98. The Malibu toymaker benefited from an analyst’s upgrade and news that the company had signed a U.S. licensing agreement to manufacture and market action figures and other products based on Teenage Mutant Ninja Turtles.

Small drug companies continued to struggle under wider challenges in the biotech sector. Pasadena nanotech drug developer Arrowhead Research Corp. fell 20 percent to $12.77. Westwood cancer drug developer Puma Biotechnology Inc. fell 9 percent to $73.37.