Five takeaways from the 2018 report:

C.E.O.s get paid regardless of logic

When Tesla announced its multibillion-dollar award for Mr. Musk in January 2018, it was hailed as a bold experiment, fitting of a visionary entrepreneur. Sure, the multibillion headline number was big enough to appease the gods, but the award was structured in such a way that Tesla would have to reach highly ambitious milestones for Mr. Musk to receive any of it. Tesla’s market capitalization is now $35 billion. To gain all the options in the award, its market value would have to increase 18 times over , to $650 billion.

“Elon’s entire compensation is directly tied to the long-term success of Tesla and its shareholders, and none of the equity from his 2018 performance package has vested,” said Kamran Mumtaz, a spokesman for Tesla.

The award’s structure was driven by concern that Mr. Musk’s attention could wander to his other ventures, like SpaceX, or that he could leave Tesla altogether. In describing the compensation package, the board said it wanted to “motivate Mr. Musk to continue to not only lead Tesla over the long term, but particularly in light of his other business interests, to devote his time and energy in doing so.”

In the months after Mr. Musk’s focus was supposedly fortified, however, both he and the company faltered. The company struggled to produce and deliver its electric cars, senior executives departed and financial concerns returned. Mr. Musk posted messages on Twitter about a deal to take Tesla private that the Securities and Exchange Commission later described as false and misleading. (Both Mr. Musk and Tesla settled with the agency.)

Why grant Mr. Musk the award at all? Analysts for Institutional Shareholder Services said at the time that because Mr. Musk already owned roughly a fifth of Tesla, his financial interests were already strongly aligned with the company. If its value hits $650 billion, his stake could be worth more than $100 billion , so it’s unclear what extra incentive a $2.3 billion carrot provides. Jeff Bezos, Amazon’s chief executive, did not require huge additional equity grants to inspire him to build his company.

C.E.O.s get paid extra to do the basics

Two chief executives who ended high up on Equilar’s list, Robert A. Iger of Disney and John J. Legere of T-Mobile, are getting awards for leading their companies through large mergers.

But carrying out mergers could be considered a core part of a C.E.O.’s job description, and not deserving of extra pay. CVS, for instance, gave a few senior executives a special award for overseeing its big merger with Aetna, but its chief executive, Larry J. Merlo, did not get one.