Slack’s stock price dropped from $9,10 to just $1,85 on Tuesday, with the firm’s stock trading at just $8.60 a share, just a tenth of its value on Monday.
That’s a drop of nearly $2 billion.
The stock has been in a slump since the beginning of the year.
Slack, founded in 2010, was spun off from rival social media company Trello to become a standalone company.
The company has since become the largest Slack-powered service in the world, with over 5 million users and more than 1.5 billion messages posted.
The firm has been hit by layoffs and consolidation, and has been trying to reinvigorate its growth with the release of new products and services.