Box, the enterprise storage and collaboration company, has reportedly filed for an initial public offering of its stock. Quartz and the Wall Street Journal are reporting that the company has filed confidential paperwork to go public, under a provision of the JOBS Act that allows companies with less than $1 billion in annual revenue to prepare to go public in secret. The nearly eight-year-old Box has raised more than $400 million and is valued at $2 billion. It began as a dorm-room project at USC for CEO Aaron Levie and his co-founder, Dylan Smith.