Tesla market capitalisation zoomed past Ford as investors bet Elon Musk can deliver on ambitious growth targets pegged to the mass-market Model 3 that will roll out later this year.
The electric-carmaker climbed as much as 5.7 per cent a day after beating analysts' estimates by reporting shipments of 25,000 cars and SUVs in the first quarter.
Its market value is now $47.6 billion (NZ$68b), $2.7b (NZ$3.8b) more than Ford.
Tesla has supplanted Ford even though it delivered fewer than 80,000 vehicles globally last year, compared with 6.7 million from Ford, the second-biggest automaker in the country behind General Motors.
"I don't know if people want electric cars, but people want Tesla," Ben Kallo, an analyst at Robert W. Baird & Co, said by phone.