Elon Musk is on the brink. In an emotional, hourlong interview with The New York Times, Mr. Musk, the chief executive of Tesla and SpaceX, described what he called the most difficult year of his career. Over the last 16 months, he has gone from seemingly on top of the world to facing one of the most intense existential crises of his entrepreneurial career.

April 10, 2017

Tesla becomes the most valuable American carmaker

Over the course of one week, Tesla leapfrogged Ford and General Motors in terms of market capitalization — a measure of a public company’s value. As Mr. Musk articulated it, Tesla is going to change the world, and it has been primed to cash in on the two transformative trends in the industry: the shift to electric vehicles as part of a broader societal move to cleaner energy, and the advent of automated driving.

The proof? Tesla later in the year planned to release its first mass-market vehicle, the Model 3, something that promised to reach drivers at a substantially different scale. Wall Street appeared to buy the pitch.