"In terms of the product, it's very good," said Karl Brauer, executive analyst at iSeeCars.com. "The innovation throughout the R1T is quite impressive. It looks good, drives well and has proven to be relatively well executed, at least by the standards of a new product from a new company, showing minimal post-launch problems."

The downside to Rivian's first year of production has been financial losses the company attributes to investing huge amounts of money before a significant number of vehicles are produced and sold. That ramp-up has been further slowed by supply-chain constraints that have cut output in half this year at the Normal plant.

"It's a plant that's designed to produce a lot more than what it's done so far this year," CEO RJ Scaringe said at the Redburn CEO conference Nov. 29. "And that's a painful way to operate a large manufacturing facility."

The Normal plant's production capacity is 150,000 vehicles a year across two assembly lines for the R1T, R1S and EDV van, which comes in three sizes. Rivian was hoping to produce 50,000 vehicles this year, but is now forecasting 25,000. That leaves a lot of cash on the table.

Scott Painter, the founder of car-subscription startup Autonomy and former CEO of TrueCar, has ordered 1,000 Rivian vehicles for Autonomy's fleet. Although Rivian is burning through a lot of cash, Painter said, it also has strong financial partners like Amazon that provide stability.

"Ten years ago, nobody would have been able to lose $4 billion a year doing anything," Painter said in an interview last month. "You have some good anchor shareholders that are going to give that company the ability to figure it out. But they certainly can't scale negative financial growth for very long."

Cash burn is becoming a major issue among investors who once pushed Rivian's valuation above General Motors and Ford Motor Co. Rivian's stock price has fallen about 75 percent since last year's IPO. Even at the lower price and valuation, some financial analysts say they're betting against Rivian.

"At 25,000 vehicles they may produce this year, that's a million dollars per vehicle, if you look at the market cap of $25 billion," said Steve Weiss, managing partner at Short Hills Capital Partners.

Rivian said it has enough cash to execute its product ramp-up and develop more mainstream vehicles on a new platform it calls R2. The automaker also has announced plans to build a second assembly plant in Georgia for those smaller vehicles.

"We have a strong balance sheet with $14 billion in cash that offers the flexibility to navigate these uncertain economic times," Scaringe said on the company's earnings call last month. On the same call, CFO Claire McDonough said: "We expect the R2 platform will unlock a massive global market expansion opportunity for Rivian."

Rivian reported a $1.7 billion net loss in the third quarter on revenue of $536 million. The company delivered 7,363 vehicles, including vans.

Rivian said its order backlog was 114,000 for the R1T and R1S, in addition to Amazon's initial order for 100,000 EDVs. Rivian also announced it will push back the R2 platform by one year to 2026.

Rivian is not alone among U.S.-based EV startups facing losses amid ongoing supply-chain issues.

Lucid Group Inc. reported a third- quarter net loss of $670 million. It has cut its production forecast twice since last year and now expects to produce 6,000 to 7,000 of its Air electric sedan this year.

Lordstown Motors Corp., Canoo Inc. and Faraday Future are among EV startups that have struggled to raise money for initial production. Lords-town delivered its first batch of 500 electric pickups for commercial fleet customers on Nov. 29. Canoo and Faraday Future have yet to deliver their first vehicle to customers.

But Rivian remains in the best shape in terms of cash, vehicle output and plans to move into the mainstream.

The R1T starts at $73,000, excluding shipping, and the R1S starts at $78,000. Rivian hasn't announced price levels for R2 vehicles but has suggested significantly lower production costs.