What's in this crop of CEO letters to shareholders? The letters are sent alongside the company's proxy statement, which is filed with the Securities and Exchange Commission. Companies usually send them out in the spring because proxy statements are due within four months of every company's fiscal year ending.​ ​​

While most of them rightfully boast accomplishments and gains, some CEOs took the opportunity this year to shine a light on the not-so-great events of the past year.