(Reuters) – Tesla (NASDAQ) Inc boss Elon Musk stated on Thursday that high production and breakeven liquidity would be Rivian Automotive Inc’s “true tests”, just a few days after its blockbuster debut in the market for electric vehicles.

“There have been hundreds of automotive startups, both electric and combustion, but Tesla is (the) only American carmaker to reach high volume production & positive cash flow in past 100 years,” Musk said in a tweet https://twitter.com/elonmusk/status/1458905811896446977.

“I wish they are (Rivian), able achieve high production, breakeven cash flow. It is their true test.

Rivian was the largest initial public offering in history, raising $12 billion. Its market value soared to more than $100billion as the shares surged. This made Rivian the second-most valuable American automaker after Tesla.

Rivian has only just begun selling vehicles. Musk did not respond immediately to Rivian’s tweet.

Musk responded to a follower by pointing out that Tesla has been selling the Roadster for more than two years and had plans to launch Model S once it goes public ten years ago.

Tesla launched its IPO in 2009 and has since increased production to ship approximately 500,000 cars annually. The company also entered the trillion dollar market value club last month.