Stewart Butterfield (C), co-founder and chief executive officer of Slack, and Allen Shim (2nd L), chief financial officer of Slack, ring the opening bell the New York Stock Exchange (NYSE), June 20, 2019 in New York City.
Drew Angerer | Getty Images
Shares of Slack rose as much as 15% Wednesday following a Wall Street Journal report that Salesforce held talks to buy the company.
Salesforce shares dropped more than 2.5% on the news.
This is a developing story. Please check back for updates.
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