What happened 

Some EV stocks were having an unusually good day today after Chinese electric automakers Nio (NIO -6.84%) and Li Auto (LI -0.74%) released their vehicle delivery numbers for October. Both companies increased vehicle production on a year-over-year basis but fell on a sequential basis. 

But Rivian's (RIVN -10.39%) share price likely dropped after a report was published yesterday that said the EV maker is postponing some R1T trucks that were ordered with a specific battery and motor configuration.

As a result, Nio's stock was up by 8%, Li Auto's shares gained 2.6%, and Rivian's stock fell by 3.6% as of 11:57 a.m. ET. 

A blue car in a factory.

Image source: Nio.

So what 

Nio said today that its October vehicle deliveries totaled 10,059 -- an impressive 174% increase year over year. That number puts the total amount of year-to-date vehicle deliveries at 92,493. 

While investors were happy with the results, Nio's deliveries actually fell by 7.5% from the previous month. Nio's management said that supply chain issues and COVID restrictions were to blame for the drop. 

"The vehicle production and delivery were constrained by operation challenges in our plants, as well as supply chain volatilities due to the COVID-19 situations in certain regions in China," the company said in a statement. 

Fellow Chinese EV maker Li Auto also released its October vehicle delivery numbers today, and they followed a similar storyline as Nio's. Vehicle deliveries increased by 10,052 during the month -- a 31% increase year over year -- but a 13% decrease from September. 

Li Auto's stock popped by more than 10% this morning on its delivery news but lost a significant portion of those gains by late morning.

In addition to the deliveries news, Nio and Li Auto's stock prices also likely benefited this morning as several news outlets said that there were unconfirmed reports that China may back off of its strict zero-COVID policies early next year. Lockdowns in the country have hampered vehicle production in China over the past two years, so any rollback of current policies would be a welcome change by the companies and their investors. 

Finally, Rivian's shares climbed as much as 4% in early trading but lost ground by late morning. The reason for the drop may be coming from a report published yesterday that said Rivian is postponing deliveries of a specific configuration of its R1T pickup truck. 

InsideEvs said that customers that preordered Rivian's quad-motor R1T with the company's largest battery pack (called the Max pack) will have to wait until 2024 to receive their orders. Orders of the dual-motor R1T with the Max pack will start in the summer of 2023, InsideEvs said. 

Rivian's investors are sensitive to any vehicle delivery changes right now after the company had to revise its full-year production numbers back in March and has dealt with rising costs and supply chain issues. 

Now what 

Nio, Li Auto, and Rivian's share price shifts today show just how volatile EV stocks still are right now. While Nio and Li Auto made gains today, the companies' share prices are down significantly over the past year. 

And while Rivian was down today, the company's share price was rising just yesterday after an analyst maintained his buy rating on the EV stock. 

Investors won't have to wait much longer to get a better understanding of how these electric vehicle companies are doing right now. Rivian will report its third-quarter results on Nov. 9, followed by Nio on Nov. 10 and then Li Auto on Nov. 18.