• SoftBank sold its stake in Slack over the second and third quarters this year, so it just missed out on Salesforce's premium acquisition price.
  • The Japanese investor sold its stake in Slack for over $1 billion, fully exiting on September 4. 
  • Salesforce said on Tuesday it would purchase Slack for $27.7 billion in cash and stock.
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SoftBank was a major investor in Slack when it was a startup raising huge sums of money from venture investors. Slack went public in June, 2019, and up until September, SoftBank remained a major shareholder.

But SoftBank exited its entire stake in the workplace-communications company just two months ago, it told investors on September 30, which means it's missing out on the premium acquisition price that Salesforce is ready to pay.

Salesforce said on Tuesday it plans to purchase Slack for $27.7 billion in cash and stock. Specifically, Slack shareholders will receive $26.79 in cash and 0.0776 shares of Salesforce common stock for each Slack share. Salesforce shares were trading at $241.35 by close of market Tuesday, so that amounts to about $45.51 per share. 

SoftBank sold off its shares across the second and third quarters of 2020, records show, a period of time when Slack's share price ranged from around $25 to a short-lived peak of just under $40 in mid-summer. The Japanese investor was fully out of its stake by September 4 when the share price was just under $34.

SoftBank did well by Slack. It originally led Slack's October 2017 funding round and bought in on following rounds. All told, it paid $334 million for its stake and sold for just over $1 billion, it said. It bought its stake from 2017 to 2018 at between $8.70 and $11.91 a share, according to Slack's IPO prospectus. 

The money came from the first Vision Fund, a $100 billion behemoth that invested in companies ranging from WeWork to Uber to robot pizza company Zume. SoftBank senior managing partner Deep Nishar led the investment.

Should Salesforce's megadeal buy of Slack proceed as planned, expected to close by July, 2021, it will be a boon to many Slack investors, including venture investors Accel and Social Capital's Chamath Palihapitiya. But SoftBank bowed out early.

SoftBank did not immediately respond to a request for comment.