Dropbox's CEO declared it as a fact last year and it has been widely reported: https://www.bloomberg.com/news/articles/2016-06-14/dropbox-ceo-pushes-toward-pro

Dropbox's CEO declared it as a fact last year and it has been widely reported: https://www.bloomberg.com/news/articles/2016-06-14/dropbox-ceo-pushes-toward-profitability-in-a-post-unicorn-era https://www.bloomberg.com/news/articles/2016-06-14/dropbox-c... https://www.wsj.com/articles/dropbox-ceo-were-cash-flow-positive-1465938538 https://www.wsj.com/articles/dropbox-ceo-were-cash-flow-posi... https://techcrunch.com/2016/06/14/dropbox-says-it-is-cash-flow-positive-in-no-rush-to-ipo/ https://techcrunch.com/2016/06/14/dropbox-says-it-is-cash-fl... But I have not personally inspected their financial statements and conducted an audit to confirm this with my own two eyes, if that's what you're asking.