What happened

With the week drawing to a close, Rivian Automotive (RIVN 6.10%) is having another "down" day: Its share price had sunk by 5% as of noon ET Friday.

So what's ailing Rivian stock now?

Simple red arrow declining stock chart on a white checked background.

Image source: Getty Images.

So what

On Thursday, as you've probably heard, Rivian stock slumped following the Wednesday publication of a New York Times article that highlighted production delays, and the EV-maker's failure to meet its own target of producing 1,200 electric trucks in 2021. (Rivian did, however, produce 1,000 EVs last year, so it wasn't too far off.)

Presumably, lingering negative sentiment from that article was contributing to Rivian's stock decline Friday -- but The New York Times wasn't the only newspaper calling out issues at Rivian this week. The Seattle Times did, too.

In addition to covering many of the same facts that The New York Times covered earlier, on Thursday The Seattle Times ­added another twist to the story: Specifically, its article notes that Rivian CEO R.J. Scaringe seemed "unwilling to share some basic details" in response to analysts' queries as to whether the production delays affecting its electric trucks were also affecting production of the electric delivery vans that Rivian has agreed to supply to Amazon.

"The company has not disclosed whether it met its 2021 goal to start delivering vans to Amazon and would not comment when asked," said the newspaper. Likewise, Amazon has "declined to say whether it received the vans last year."

Now what

Coming on top of Rivian's already well-publicized failure to meet its 2021 production target for electric trucks, the possibility that it may also be falling behind on the timeline of its massive contract with Amazon may be an even bigger worry.

After all, under its contract with Amazon, Rivian is to deliver 100,000 electric vans to the e-commerce giant by 2030 -- and that's more than the sum total of all the pre-orders it has collected so far for its consumer-market EV models. If Rivian is in fact tardy on the Amazon contract, that would help to explain why Amazon recently ordered electric delivery vans from Stellantis, the automaker formed a year ago by the merger of Fiat Chrysler and French automaker Peugeot.  

It would also be a big reason to start worrying about Rivian stock.