Check out which companies are making headlines after the bell on Thursday:

Shares of Viacom fell more than 6 percent after initially jumping nearly 4 percent during after-hours trading. The company reported earnings of $1.17 per share on revenue of $3.36 billion, topping expectations for $1.05 per share on revenue of $3.29 billion, according to Thomson Reuters consensus estimates. Domestic ad revenue fell in the quarter, however.

GoPro shares surged more than 12 percent in extended trading after the consumer electronics company posted its second-quarter results. The tech company reported a narrower-than-expected loss of 9 cents a share on revenue of $296.5 million, while Wall Street expected a loss of 25 cents a share on revenue of $269.6 million, according to Thomson Reuters consensus estimates.

Shares of Yelp skyrocketed more than 18 percent during after-hours after the crowd-sourced review company posted an unexpected profit in its second-quarter. The company reported earnings of 9 cents a share on revenue of $209 million while analysts projected a loss of 3 cents on revenue of $205 million, according to Thomson Reuters consensus estimates. The company also announced a $200 million stock buyback plan and a deal to sell Eat24 to GrubHub.

Weight Watchers shares soared nearly 17 percent during extended-trading after the company posted results that beat Wall Street expectations. The diet services company reported earnings of 67 cents a share on revenue of $342 million, while Wall Street predicted earnings of 51 cents a share on revenue of $330 million, according to Thomson Reuters consensus estimates.

Source: Tech CNBC
After-hours buzz: YELP, WTW, GPRO & more