Lucid Group Inc., in market trading Tuesday, became the latest electric-vehicle startup to rival automotive icon Ford Motor Co. in market value, another example of how investor enthusiasm is intensifying for car companies that shun gasoline.

Stock in Lucid, a maker of high-end electric cars, climbed roughly 15% in morning trading, following the release of its first financial results as a public company Monday afternoon. The rally pushed the company’s valuation to $83 billion as of midday, surpassing that of Ford for the first...

Lucid Group Inc., in market trading Tuesday, became the latest electric-vehicle startup to rival automotive icon Ford Motor Co. in market value, another example of how investor enthusiasm is intensifying for car companies that shun gasoline.

Stock in Lucid, a maker of high-end electric cars, climbed roughly 15% in morning trading, following the release of its first financial results as a public company Monday afternoon. The rally pushed the company’s valuation to $83 billion as of midday, surpassing that of Ford for the first time since Lucid’s debut on the public markets over the summer.

Company executives provided an upbeat outlook for Lucid on an analysts call Monday, highlighting an increase in reservations for its first model, the Lucid Air, and plans to expand its manufacturing output at its factory in Arizona.

The Newark, Calif.-based startup reported a net loss of $524 million for the third-quarter, in part due to higher costs associated with starting vehicle production in late September and increasing its employee headcount for sales and service operations. It said it had raised $4.4 billion from a reverse merger deal that took it public in the summer and had enough cash to ramp up operations through 2022.

Also on Monday, car enthusiast magazine MotorTrend gave the Lucid Air its prestigious Car of the Year award, saying it was the first time a debut model from a new car company has ever received the accolade.

Lucid’s rising market valuation comes as other automotive startups are emerging to challenge the traditional car companies in the race to dominate the future of the automobile.

Rivian Automotive Inc. , another new electric-vehicle maker focused on trucks and SUVs, went public last week with a market value that quickly overtook Ford’s and has since surpassed that of General Motors Co. Valued at about $138 billion in trading Tuesday, Rivian is now roughly on par with German auto-making giant Volkswagen AG.

A spokesman said Ford’s strategic plan, outlined in May, has positioned the company to emerge as a leader on electric vehicles. The company recently committed $7 billion for three new battery factories, in Tennessee and Kentucky, along with a plant to build electric pickup trucks, part of $30 billion in electric-vehicle investment planned through 2025.

“Markets are efficient over time,” he said. “We expect to create great value for customers and all our stakeholders.”

Rivian raised $13.7 billion in all from its offering, a haul that is among the largest for a U.S. public listing. Its stock has continued to rise, climbing more than 91% from the $78 IPO price, as of Monday’s close.

Lucid Chief Executive Peter Rawlinson said the enthusiasm around Rivian’s debut is an important endorsement for some of the challenger brands and the prospects for electric vehicles overall.

“A rising tide raises all boats,” said Mr. Rawlinson, in an interview. “We can co-exist very comfortably,” he said, of sharing the marketplace with Rivian.

Under Chief Executive

Jim Farley, who took over last year, Ford has generated electric-vehicle buzz of its own. Its Mustang Mach-E electric SUV, a competitor to the Tesla Model Y, has received critical praise. Ford has more than 160,000 nonbinding orders for its electric F-150 Lightning pickup truck, scheduled to go on sale this spring.

Ford’s shares also have been on a run, up 125% this year through morning trading Tuesday, the seventh-largest gain in the S&P 500, according to Dow Jones Market Data.

Still, many investors are tilting their bets to new startups like Lucid that are solely focused on electric cars and have similarities to Tesla Inc. , in how they plan to go to market.

Lucid was one of several aspiring electric-car manufacturers to go public in recent years, making its debut in July after merging with a special-purpose acquisition company. It began delivering its first Air sedans in October and plans to sell roughly 575 of them by the year’s end. Revenue from the company’s first car sales will be reflected in Lucid’s year-end financial results, executives said.

On Monday, Lucid said it had more than 17,000 reservations for the new model, up from the 13,000 previously disclosed. Those reservations represented an order book of about $1.3 billion, the company said.

Lucid executives said they are currently focused on ramping up production of the Lucid Air, a model that is considered by many in the industry to be a direct Tesla competitor. It plans to introduce a second model, a battery-powered SUV called the Gravity, in late 2023.

—Mike Colias contributed to this article.

Write to Ben Foldy at Ben.Foldy@wsj.com