In this video from Monday's edition of Investor Beat, host Chris Hill and Motley Fool analysts Taylor Muckerman and Jason Moser dissect the hardest-hitting investing stories from the market today.

SolarCity (NASDAQ:SCTY.DL) hit an all-time high today, after the stock got an upgrade from Goldman Sachs. Twitter (NYSE:TWTR), on the other hand, was down today on news of another downgrade for the high-flying new social-media stock, this time coming from Morgan Stanley. SiriusXM (NASDAQ:SIRI) rose today on the first day of trading since Liberty Media (NASDAQ:FWONA) announced it wanted to acquire the entire company; Liberty currently owns about 53% of SiriusXM. And finally, Pandora (NYSE:P) saw a big pop today, on news that its number of active listeners for December was up 13% year over year. In this segment, Taylor and Jason discuss four stocks making moves on the market today.