Sources: Salesforce has held talks about acquiring Slack, although a deal is not guaranteed; Slack stock jumps 20%+ while Salesforce falls ~4% (Wall Street Journal)

Wall Street Journal:
Sources: Salesforce has held talks about acquiring Slack, although a deal is not guaranteed; Slack stock jumps 20%+ while Salesforce falls ~4%  —  A deal would likely value Slack at more than $17 billion and mark Salesforce's largest acquisition ever  —  Salesforce.com Inc. has recently …