In a surprising move, Snap Inc. has confidentially filed for an initial public offering. The parent company to Snapchat is looking to raise as much as $4 billion, which would put the company's value between $25 billion to $35 billion. The result would make it the biggest United States stock market debut in two years.

The IPO would follow in the steps of Chinese e-commerce giant Alibaba Group Holdings Ltd., which went public two years ago valued at $170.9 billion. Snap's IPO would be the biggest by a U.S. technology company since Facebook in 2012 with a value of $81.2 billion. Snapchat and Facebook are currently going toe-to-toe with each other for users.

The IPO filing was done with the Securities and Exchange Commission, and it was done in confidentiality under the U.S. Jumpstart Our Business Startup Act. Twitter took a similar approach back in 2013. It allows companies with revenues less than $1 billion to test investor appetite while maintaining the secrecy of their financials.

The move to file for an IPO is evidence that Snap is looking to grow. This comes after CEO Evan Spiegel declined a multi-billion dollar offer from Facebook in 2015. Since then, Snapchat has been fending off clone-like competition from Facebook, and it is looking to release its new Snapchat Spectacles. The IPO is expected to happen in early 2017, possibly March.