4 CEOs With A Tough Year Ahead

This week, everyone is returning to business as usual, renewed, refreshed and with the clean slate of a new year in front of them. However, for some CEOs, the problems that 2015 drummed up are far from blurs in the rearview mirror.

Several big names on Wall Street are likely to make some tough decisions in the upcoming year in order to preserve their companies and prove their ability to steer their firm through turbulent waters.

Monty Moran And Steve Ells

Fast food chain Chipotle Mexican Grill, Inc. CMG co-CEOs Monty Moran and Steve Ells are beginning the year with a mess on their hands. The once popular burrito chain has had several outbreaks of foodborne illnesses, causing the company to close dozens of restaurants.

Not only did the outbreaks cut into the company's bottom line, but Chipotle's reputation, which has been based on offering honest, healthy food, has been severely tarnished. Now, with customers unsure about the chain's safety standards and several new store openings planned for 2016, it will be up to Moran and Ells to navigate through the coming year and win back the public's trust.

In 2015, Ells pledged to make Chipotle "the safest place to eat," but the bigger task will be convincing customers that they've made good on that promise.

Related Link: Chipotle Goes From "Mo-Mo" To "No-No" In 2015

Jack Dorsey

Social media site Twitter Inc TWTR has had a turbulent year, as investors questioned the firm's ability to continue growing. Over the past 12 months, Twitter's shares have fallen 38.46 percent, and despite the fact that the company has been able to grow its revenue, traders have been hesitant to invest due to lackluster user growth.

The site has been struggling to add new users, a major factor when it comes to long-term success. CEO Jack Dorsey has acknowledged the issue and promised to continue offering features designed to attract new signups and boost the site's user base in the coming year.

He was the catalyst behind Twitter's latest offering, Moments, which has proven to be successful so far. Under Dorsey's leadership, the firm is expected to step up its marketing efforts in 2016 as well.

Marissa Mayer

Yahoo! Inc. YHOO CEO Marissa Mayer has an uphill battle ahead of her in the coming year; the new mom to twins has been struggling to fend off critics who say she has failed to keep the Internet company from sinking.

At the end of 2015, Mayer decided to abandon plans to spin off Yahoo's stake in Alibaba Group Holding Ltd BABA for fear of tax implications. Instead, the firm is planning to sell its core Internet business, which has been valued between $2 and $4 billion.

Mayer's four-year stint at the helm has been under the microscope recently, as the company has seen several top executives jump ship, leading many to believe that the firm is in its final days.