Carmakers say new models should also help lift the industry in 2021, after a 15 percent decline in its slowest year since it recovered from the Great Recession.
The milestone seemed unreachable just three years ago and comes as Tesla has seen a string of profitable quarters and a buoyant stock.
Investors are betting that small companies like Workhorse will help popularize electric commercial vehicles. And Tesla aims to extend its reach.
Mr. Musk said on Tuesday that he had moved to be near a new factory Tesla is building outside Austin.
A new agreement, supplying hydrogen fuel cell technology from General Motors, is less sweeping than the strategic partnership outlined in September.
General Motors says it will increase its investment and model offerings over the next five years “to expedite the transition to E.V.s.”