Wednesday's After-Hours Movers: Yelp, Glu Mobile And More

Key Energy Services, Inc. KEG soared 24 percent to $2.33. The oil well servicing contractor was slated to post first-quarter results after the bell.

Glu Mobile Inc. GLUU gained 16 percent to $6.22 on heavy volume after the online game company posted first-quarter revenue growth of 33 percent and said it signed an eight-year contract with Britney Spears.

Equinix Inc EQIX rose 5 percent to $257 after the data center services provider posted first-quarter results.

Salesforce.com, Inc. CRM extended its gains after the bell, trading up 7 percent to $75.71 on news that the company has hired an investment bank to field a takeover inquiry.

Yelp Inc YELP plunged more than 14 percent to $43.99 after the consumer review company posted first-quarter results.

Inovio Pharmaceuticals Inc INO declined 7 percent to $9.18 after the company said it plans an underwritten public offering.

Saia Inc SAIA dropped more than 7 percent to $37.89, extending earlier losses apparently touched off by the transportation company's first-quarter earnings report.

Baidu Inc (ADR) BIDU dipped about 4 percent to $210. The Chinese-language Internet search provider posted fourth-quarter results.

Valeant Pharmaceuticals Intl Inc VRX lost nearly 3 percent in the extended session, trading at $208.14. The company closed up by 4 percent after beating first-quarter expectations.

Charter Communications, Inc. CHTR bounced down by 2 percent to $184.42. The company, which closed up 3 percent Wednesday, was earlier reported to be interested in acquiring Time Warner Cable Inc. TWC.