U.S. Markets closed

Warning Signs Ahead For Unicorn Slack's Public Offering

Warning Signs Ahead For Unicorn Slack's Public Offering

Warning signs are emerging for Slack Technologies Inc., the business communications software company valued at $17 billion that goes public this week. Some Slack employees have been selling their stakes in the start-up ahead of the listing, according to data from secondary marketplace Forge, per Business Insider. Like fast-growing Uber and Lyft, Slack has a major weakness.