Shares of Slack (WORK) – Get Report were falling more than 7% after-hours after the company said in an SEC filing late Monday that IBM (IBM) – Get Report had already been its largest customer for some time and was simply expanding its usage of the workplace platform over time.
Earlier on Monday, Business Insider reported that IBM would be adopting Slack for its 350,000 member workforce, sending shares up more than 15% before trading was halted shortly before the market close, at 3:49 PM ET.
Slack also said in its filing that it was not updating its financial guidance for either its fiscal fourth quarter or full year ending Jan. 31, 2020.
