Rivian, an electric vehicle startup backed by Amazon, Ford, and other deep-pocketed investors, confidentially filed to become a publicly traded company this week.

       The initial public offering is expected to take place after the Securities and Exchange Commission completes its review process, Rivian said. The proposed offering's size and price range must still be determined.

       However, Rivian last year raised $2.5 billion from accounts advised by investment firm T. Rowe Price and it has become a standout amid fledgling EV start-ups.

       The company has a contract with Amazon to build 100,000 electric delivery vans starting this year at its factory, a former Mitsubishi plant in Normal, Illinois. Rivian also is rolling out a pickup truck and an SUV.