Elon Musk Says in Tweet He Is Considering Taking Tesla Private

A take-private deal would value the electric-car maker above $70 billion, which would be by far the biggest in history

Tesla Inc. Chief Executive Elon Musk jolted financial markets on Tuesday with a surprise proposal to take the electric-car maker private in what would be the biggest buyout in history.

About three hours into the trading day, Mr. Musk startled investors by casually stating on Twitter: “Am considering taking Tesla private at $420. Funding secured.”

The...