Tesla shares closed up nearly 22% on Thursday – their biggest single-day gain in over a decade – as Elon Musk’s bold forecast of surging sales reassured investors he was still looking to grow its core business of selling electric cars. At close, nearly $150bn was added to the company’s market value.

Musk forecast 20-30% in sales growth next year, promising to launch an affordable vehicle in the first half of 2025, and said efforts to slash production costs boosted margins in the third quarter.

The stock rose to a session high of $262.2 with volumes of roughly 200 million shares. It was the biggest gain since May 2013, and erased recent losses on concerns that Musk was distracted by new projects like the recently unveiled robotaxi.

Musk has been pivoting Tesla into an artificial intelligence and robotics company from an EV market leader, but has yet failed to lay out a detailed business plan for his new focus. Investors sold off Tesla shares earlier this month after a robotaxi event was short on details.

“With the stock selling off in October before its earnings announcement, some bears feel this is more of a relief rally, as results were better than feared,” said Ed Egilinsky, managing director at investment company Direxion.

Last quarter, Musk made bold company announcements about everything but cars – from driverless taxis to humanoid robots – leaving investors worried about dwindling margins already squeezed by lowered prices.

“He definitely seemed more passionate and invested in it this time,” said Jessica Caldwell, head of insights at car research and buying website Edmunds.

“I feel like so much of Tesla is tied up in the future but we need to figure out how you get there. That’s what people needed to hear and they were a little bit better in providing those details than they have been in the past.“

Tesla reported third-quarter margin that handily beat Wall Street expectations and said that the labor and material costs of making vehicles – known as the cost of goods sold per vehicle – dropped to its lowest-ever level, about $35,100.

It recorded $326m in revenue for its autopilot software called Full Self Driving (FSD) used in Cybertruck and other autonomous features.

“FSD played a part in the margin expansion, but I think the larger driver was reduced unit production costs … Over time, FSD should drive higher long-term margin expansion,” said Seth Goldstein, equity strategist at Morningstar.

FSD is the bedrock for Tesla’s robotaxis.

Musk said he expects Tesla vehicles to offer paid, driverless, ride-hailing services next year, doubling down on his promise made at the robotaxi event. But that plan is likely to face significant regulatory challenges.

Not all investors are likely to be mollified by Tesla’s reassurances on Wednesday.

Ross Gerber, chief executive of Gerber Kawasaki Wealth and Investment Management and a prominent Tesla investor, said robotaxis and AI were not the fundamental businesses he wanted Musk to focus on.

“The days were good when Elon slept at the factory. He was there every day, working. Not going on Trump rallies of all things he could be doing,” Gerber said, referring to Musk’s well-publicized support of the Republican presidential candidate.