SAN FRANCISCO ― Dropbox is the latest so-called unicorn to trot into the public markets.

Some 36 million shares in the company, based in San Francisco, were sold on Thursday (March 23) for US$21 (S$28) apiece, higher than the range of US$18 to US$20 a share that the company’s investment bankers had recently envisioned.

Founded in 2007 by two Massachusetts Institute of Technology computer science students, Drew Houston and Arash Ferdowsi, Dropbox sells software subscriptions that let users collaborate and share files online.

Until now, it was financed by private investors — including venture capital firms Sequoia Capital and Accel Partners — who valued the start-up at US$9.4 billion, according to the research firm CB Insights.

That large valuation earned Dropbox the coveted “unicorn” designation, which applies to start-ups valued at more than US$1 billion.

The share sale on Thursday gave Dropbox a market value of about US$9.2 billion. The shares are expected start trading on Friday on Nasdaq under the ticker symbol DBX.

The debut comes during a period of market turmoil. On Thursday, stock market indexes plunged more than 2 per cent as investors fretted about the prospect of a trade war between the United States and China.

Dropbox’s initial public offering could pave the way for other unicorns to soon go public, letting their early investors and founders cash in on huge investment gains that currently only exist on paper.

Dropbox has never turned an annual profit, but the company has achieved annual sales growth of more than 30 per cent in recent years, with its revenue topping US$1 billion annually. Its losses have narrowed to US$112 million last year from US$326 million in 2015, and the company says it is moving toward becoming profitable.

The demand for Dropbox’s shares suggests investors overcame any concern about daunting competition from the likes of Microsoft, Google and Amazon, all of which provide cloud storage services.

Dropbox’s debut is a bright spot for the tech sector, where the expectation of greater government regulation in the United States and Europe has hurt companies’ shares in recent days. THE NEW YORK TIMES