This article is more than 2 years old.

January 30, 2014 This article is more than 2 years old.

Box, the online storage company, has secretly filed paperwork for an initial public offering, according to a source.

That means Box could start trading as a public company before its chief rival, Dropbox. Both are among the most anticipated tech IPOs of this year.

A new law allows companies with less than $1 billion in annual revenue to confidentially file drafts of their IPO prospectus with the US Securities and Exchange Commission. Twitter is the most prominent company to have taken advantage of this provision of the JOBS Act. We’ve already declared 2014 to be “the year of the secret IPO.”

“We don’t have anything to share at this time. We’re focused on continuing to build our business and expand our customer relationships globally,” a Box spokesman told Quartz in an emailed statement.

Box has already tapped banks, including Morgan Stanley, Credit Suisse, and JP Morgan Chase, to help underwrite it stock offering. It raised more than $100 million (paywall) in 2012, at a valuation of more than $1 billion. The venture-backed firm run by under-30 wunderkind Aaron Levie could be looking to raise about $500 million in an IPO.

Dropbox recently raised $250 million in a funding round led by a BlackRock investment fund; its valuation was $10 billion. Dropbox has traditionally focused on consumers but more recently pushed to expand into the corporate world. Box, by contrast, is going after consumers after building an enterprise storage business. It recently offered 50 gigabytes of free storage to users of its new mobile apps.

This post has been updated with Box’s statement.