4 Executives Who May Be On Thin Ice in 2016 (CMG,TWTR)

The year 2015 turned out to be a disappointing one for the stock market in general and for many companies in particular, which always leads to speculation over which company executives could be on the chopping block in the coming year. The following executives may be close to exhausting the patience of investors who see their returns slipping away.

CEOs Steve Ells and Monty Moran of Chipotle Mexican Grill

The contaminated food scandal engulfing Chipotle Mexican Grill Inc. (NYSE: CMG) has gotten so bad, the company has had to defend itself against rumors the E. coli outbreak stemmed from the use of dog and cat meat. The company is also under criminal investigation for a norovirus outbreak in one of its California restaurants.

In the face of rapidly declining sales, the first decline since its initial public offering (IPO), CEOs Steve Ells and Monty Moran have gone on an apology tour, with vows to put food safety before profits. This may have stopped the bleeding temporarily, but they have a lot to overcome to regain investors' confidence.

It also does not help when a company’s CEO compensation package becomes a point of controversy. Investors have been making a lot of noise about Ells’ and Moran’s compensation, which topped $57 million in 2014, not including the $41.6 million Ells raked in from exercising stock options. Ells and Moran have been able to deliver consistent year-over-year revenue increases, but the margins may be running out of their menu. The brand has been tarnished, and the board may be sensing the time has come for a change.

CEO Jack Dorsey of Twitter

The slowing pace of Twitter Inc.’s (NYSE: TWTR) growth has been a major concern since its IPO in 2013. Its stock, which traded as high as $69 a share just after the IPO, hit an all-time low of $17.61 as of January 2016.

This is not an ideal situation for a new CEO to take on, but Jack Dorsey is the co-founder of Twitter and probably has as good a grasp as anyone on what it takes to turn things around. Former CEO Dick Costolo managed to drive many of the top C-level executives from their suites, leaving Dorsey to rebuild a core management team. All of this comes at a time when Twitter is losing user confidence due to worsening harassment issues.

The good news is revenues continue to grow. The bad news is the growth is not coming from an expanding user base; rather, it is coming from increased monetization. Investors have been frustrated over the lack of new features and upgrades being developed that could attract and retain users. Dorsey says he is focused on enhancing Twitter’s user experience and strengthening the market message to reach new users. It is doubtful shareholders will let 2016 slip by without some significant improvements in the numbers.

CEO Jack Dorsey of Square

Of greater concern is Square, which must be able to grow its B2B revenue and is discontinuing its relationship with Starbucks, its biggest corporate customer. Apparently Square could not make money on the deal with Starbucks. If it cannot make money with a partner such as Starbucks, is there a flaw in its business model, or will it be relegated to the small business space? Dorsey must be able to show how Square can grow and become profitable, or it is more likely shareholders may force him out of his day job.

The CEO of Twitter is also the CEO of Square (NYSE: SQ), the payment-processing company Dorsey co-founded that went public in 2015. Both companies are at a very vulnerable point in their development, yet Dorsey appears to be pulling half duties as CEO of Twitter and CEO of Square. Twitter's IPO was not considered a raging success, and its share price is trading below the issue price.

CEO Marissa Mayer of Yahoo

Since Marissa Mayer was hired as Yahoo’s (NASDAQ: YHOO) CEO in 2012, its share price has more than doubled. It reached a high of $50 a share in November 2014 but is trading at $29 as of January 2016.

Analysts say Mayer merely rode the wave of Alibaba’s valuation over the last couple of years since its IPO without contributing much value to the core business. In fact, analysts have placed no value on its core Internet properties, attributing most of the company’s $35 billion valuation to its Alibaba holdings.

In an effort to increase shareholder value, the company planned to spin off its huge stake in Alibaba in 2015, but then canceled those plans over concerns of tax implications. As of 2016, the company is considering alternatives for separating itself from Alibaba, including selling off its core Internet properties. Mayer’s leadership, which was beginning to come under scrutiny leading up to the Alibaba spin-off, will come under even more scrutiny as anxious investors are forced to wait and see how Yahoo goes about maximizing shareholder value.

For someone who is concerned with shareholder value, this is a funny way of showing it. Activist investor Eric Jackson is not laughing and has presented his case for Mayer’s ouster to the Yahoo board of directors.

It probably does not help Mayer’s cause when she presides over a company-sponsored party costing $7 million. The Great Gatsby-themed party held on San Francisco’s Pier 48 in December 2015 is a testament to Mayer’s tendency toward lavish spending, which includes buying iPhones for 22,000 employees and providing free food for workers at Yahoo headquarters.