E-signature pioneer company DocuSign has reportedly filed confidentially to go public. TechCrunch on Tuesday published a report citing sources at DocuSign saying that the company had covertly submitted its initial public offering (IPO) filing, and will announce formally in the weeks before its public debut.

DocuSign received a $3 billion valuation in 2015, and has raised over $500 million in investment funding over its 15-year lifespan. The company declined to comment for this story.

DocuSign CEO Daniel Springer has previously told reporters that the company intended to go public in 2018. “We are just getting to a place of being operating cash flow breakeven,” Springer told MarketWatch last year of his intent to take the company public.

Legal technology has typically gone the way of acquisition for its exits. Though many of the largest exits in legal tech did not disclose the exact terms of their deals, Epiq's 2016 sale to Document Technologies Inc (DTI), valued at nearly $1 billion, is often considered one of the biggest exits in legal tech to date. Online legal marketplace Avvo, which was acquired by e-commerce company Internet Brands earlier this year, had raised $132 million over its lifespan, just under a fourth of DocuSign's total fundraising.

DocuSign differs from purely legal-focused technology in that it cuts across a wide swath of various industries, with clients in the financial, healthcare and insurance industries, among others.

Though the company has operated steadily for 15 years, a somewhat long lifecycle for your standard tech “unicorn,” DocuSign has seen marked growth over the last few years. The company's last fundraising round in 2015 brought in over $300 million in investor funding. The company now provides contracts and document support to more than 250,000 companies across 188 countries, and has 2,000 employees across 12 offices globally.