Box on Monday officially announced its plans to go public, ending months of rumors and speculation.

The cloud-based file sharing and sync service company filed a prospectus with the U.S. Securities and Exchange Commission (SEC) that says it is aiming to raise $250 million in its initial public offering (IPO) .

In the S-1 filing, Box reported more 25 million users have registered with the service. Box supports more than 225,000 companies. Only 34,000 of those are paying customers. Box's largest deployment to date is more than 60,000 users.

Box ended its fiscal year in January 31, 2014 with $124.2 million in revenue, up from $58.8 million in the previous year, representing year-over-year growth of 111 percent. But the company lost more than it made. For the year ended January 31, 2014, Box saw a net loss of $168.6 million, compared to a net loss of $112.6 million the year before.

Box said in its S-1 that proceeds from the IPO would be used for general corporate purposes, including working capital, operating expenses and capital expenditures. "We currently expect to invest at least 50 percent of the net proceeds in sales and marketing activities, product development, general and administrative matters and capital expenditures to support the growth in our business. We also may use a portion of the net proceeds to acquire complementary businesses, products, services or technologies. However, we do not have agreements or commitments for any specific acquisitions at this time."

Among the investment risks Box cited, the company said it did not expect to become profitable in the foreseeable future. It also said its market is highly competitive, and it has accumulated a deficit of $361.2 million.

The IPO news follows months of rumors that Box was secretly filing for an IPO after Quartz cited an unknown source in a report in January.

Box CEO Aaron Levie, in a letter included in the filing, said, "It’s been a thrilling ride. But it’s also just beginning."

"Companies that don’t find ways for information to enhance their competitive advantage will be outdone by businesses that do," he said. "To thrive, companies must arm themselves with a new understanding of the opportunities of information technology to drive their success."

Box declared EMC (EMC), IBM (IBM), and Microsoft (MSFT) Office 365 and SharePoint as its competitors in the enterprise content collaboration space, and Citrix (CTXS) ShareFile, Dropbox, Google Drive and Microsoft Skydrive Pro in the file sync and share market.

As far as Box's top competitors, Google (GOOG) slashed Drive pricing last week to make its cloud-based storage platform more affordable to users.

And Dropbox in February announced its most recent $350 million funding round, the Wall Street Journal (WSJ) reported.

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