Friday was a generally flat day on Wall Street, with barely worth noticing declines for the Dow Jones Industrial Average and other popular benchmark indexes. But from a slightly wider view, the market's performance to begin 2019 has been the best annual kickoff in years, and that's spreading some positive sentiment among investors who were hit hard by 2018's tumble. Yet a few companies in particular were the subjects of bad news that sent their share prices lower Friday. Vail Resorts (MTN -3.00%), Activision Blizzard (ATVI), and Weight Watchers International (WW -10.07%) were among the day's worst performers. Here's why their stocks did so poorly.

Vail sees an early ski slump

Check out the latest Vail Resorts earnings call transcript.

Shares of Vail Resorts plunged almost 13% after the ski resort operator warned that its early December performance had been weaker than expected. Total lift ticket revenue was higher by 12% season-to-date from year-ago levels as of Jan. 6, with similar-sized gains in ski school, dining, and retail/rental revenue. Skier visits were up nearly 17% during the same period. Yet CEO Rob Katz said that "despite the good conditions, our destination guest visitation was much lower than anticipated in the pre-holiday period." That caused Vail to predict its bottom line will come in below the lower end of its previous guidance. Those results could point to longer-term weakness in the snow sports industry.

Lone skier on a slope with trees and a view of the top of the mountain.

Image source: Vail Resorts.

Activision breaks off its Bungie partnership

Check out the latest Activision Blizzard earnings call transcript.

Activision Blizzard's stock price dropped more than 9% in the wake of news about a key collaborative partnership with a game developer. In a filing with the U.S. Securities and Exchange Commission, Activision said it would transfer all rights to the hit game Destiny to its developer, Bungie. As a result of the move, Activision predicted that Destiny won't have any material presence on its financial statements in 2019. Shareholders weren't happy with the news, because the game had performed well, and seemed like a good opportunity for the company to expand beyond long-standing hit franchises like Call of Duty.

Analysts slim down on Weight Watchers stock

Check out the latest Weight Watchers International earnings call transcript.

Finally, shares of Weight Watchers International lost about 5%. Stock analysts at JPMorgan cut their rating on the stock from overweight to neutral, and reduced their price target nearly by half to $37 per share. Apparently, the key New Year's season isn't going as well for the company as many had hoped, and rising competition from other quarters has started to hinder Weight Watchers' sales growth initiatives. In addition, the JPMorgan analyst pointed to the government shutdown as a possible drag on the company, suggesting that furloughed (and unpaid) federal workers were less likely to spend money to join its programs. All told, Weight Watchers will have to demonstrate greater resolve of its own if it's going to make good on its long-term potential.