Check out the companies making headlines after the bell Wednesday:

Juniper Networks soared more than 15 percent in after-hours trading after CNBC reported Nokia was in talks to buy the networking products developer for about $16 billion, about $5 billion more than its market capitalization.

Semtech stock plunged more than 10 percent after the bell. The chip maker beat on third- quarter earnings but predicted a decline in sales and profit for the fourth quarter.

Despite posting third quarter financial results that beat or met Wall Street expectations, shares of Box fell nearly 6 percent in extended trading. The cloud storage company posted a bigger loss in the third quarter from a year ago, after heavy spending on marketing to ward off competition, like DropBox and Drive, Thomson Reuters reported.

Shares of Jack in the Box fell more than 5 percent in after hours trading after the fast food chain posted earnings and revenue that missed analyst expectations.