Shares of Slack (WORK) - Get Report fell more than 7% in after-hours trade, 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 p.m. Eastern. After-hours trading resumed at 4:45 p.m. Eastern.
Slack also said in its SEC filing that it was not updating its financial guidance for either its fiscal fourth quarter or full year ending Jan. 31, 2020.
"IBM has been Slack’s largest customer for several years and has expanded its usage of Slack over that time,” the filing read. As of June 2019, around 165,000 IBM employees were using Slack, according to a company blog post.
Shares of slack were trading at $26.54 on Monday at the time trading was halted.