The stock market had a generally solid performance on Monday, with large-cap indexes posting modest gains even as benchmarks that track the changes of smaller stocks underperformed. The big news of the day came on the trade front, where the White House intervened to reverse previous policy with respect to Chinese smartphone giant ZTE in an apparent effort to gain favor with the world's most populous nation and second-largest economic power. Investors looked for potential winners from the thawing of relations with China, but not all stocks were able to avoid significant losses. Viacom (NASDAQ:VIAB), Synchronoss Technologies (NASDAQ:SNCR), and DHX Media (NASDAQ:DHXM) were among the worst performers on the day. Here's why they did so poorly.

Viacom deals with media fallout

Viacom's Class B shares fell 5% as the media giant dealt with a lawsuit from acquisition target CBS (NYSE:CBS). In the latest dispute, CBS sued National Amusements, which is controlled by the Redstone family and is a dominant shareholder in both CBS and Viacom. The lawsuit alleged that Shari Redstone has "acted to undermine the management team" of CBS by taking steps like "talking to potential CEO replacements" and "threatening to change the board" of directors. National Amusements denied the allegations, but the deal could make it difficult for a Viacom-CBS merger to go forward amid further potential questions about conflicts of interest and fiduciary duties to shareholders of both entities.

Viacom international studio storefront, with posters from various movies on a white building.

Image source: Viacom.

Nasdaq gets impatient with Synchronoss

Synchronoss Technologies stock fell about 10% after the Nasdaq Stock Market suspended trading of shares of the cloud-computing mobile specialist. Shares were no longer allowed to trade on the exchange as of the beginning of today's session, but the company said that it would quote its stock on over-the-counter markets pending its appeal of the Nasdaq decision. Synchronoss has been out of compliance with Nasdaq requirements regarding financial reporting, and although it believes that its auditors in the "final stages of completing their audit," unanticipated delays have prevented them from moving forward as quickly as Nasdaq wanted. Synchronoss will ask to get restored to regular trading once it completes its audit and files reports as required, but investors aren't sure exactly when that will happen.

DHX Media has a disappointing report

Finally, shares of DHX Media plunged 20%. The Halifax-based children's content and brand company reported fiscal third-quarter financial results that didn't live up to what investors had hoped to see, as DHX swung to a net loss despite a 49% jump in revenue from the year-ago quarter. Most of the gains came from the acquisitions of the Peanuts and Strawberry Shortcake brands, with just 3% organic growth. Investors were also likely disappointed by the results of DHX's search for strategic alternatives, which yielded only a deeper partnership with a unit of Sony rather than a full-blown buyout bid. Unless someone steps up to acquire DHX in total, some shareholders won't be satisfied with the company's efforts.

Dan Caplinger has no position in any of the stocks mentioned. The Motley Fool recommends DHX Media, NDAQ, and Synchronoss Technologies. The Motley Fool has a disclosure policy.