Stocks making the biggest moves after hours: Switch, Viacom, CVD Equipment & Cancer Genetics

Rob Roy, founder and chief executive officer of Switch Inc., center, rings the opening bell before the company's initial public offering (IPO) on the floor of the New York Stock Exchange (NYSE) in New York, Oct. 6, 2017.

Michael Nagle | Bloomberg | Getty Images

Check out the companies making headlines after the bell:

Switch shares plummeted as much as 24 percent after hours. The data storage company reported a loss per share of $2.09, which was much larger than the 12 cents Wall Street expected. Switch attributed the loss to a one-time compensation expense. Revenues beat estimates, and guidance for the upcoming year was in line with estimates.

Viacom stock dropped more than 2 percent in the extended session. Sources familiar told CNBC on Monday afternoon that a CBS bid for Viacom would value the media company below its current market valuation. This may indicate difficult negotiations to come.

Shares of CVD Equipment rallied more than 10 percent post-market after the research equipment manufacturer announced its best financial results throughout its 35-year history. Fourth-quarter revenue rose 34 percent to $9.8 million.

Cancer Genetics stock plunged more than 33 percent after the bell. The biotech company reported losses per share larger than expected and missed revenue estimates by nearly $2 million. It plans to conduct a "comprehensive and extensive" review of its strategy and organization.