The collaboration software space is hot right now and one of its top players, Slack may be looking to make the most of a seller’s market. Sources reportedly familiar with the situation tell Bloomberg that the company has fielded inquiries from several potential suitors including Amazon.

A deal, if it could be hammered out, would pin Slack with a valuation of at least $9 billion, the sources said. That’d be a significant premium over its $3.8 billion valuation from a year ago when it brought in $200 million in a round of funding.

The sources warned that a deal hasn’t yet been reached and discussions could fall apart at any time. Both Amazon and Slack declined to comment on the matter when probed by the publication.

Slack launched in the summer of 2013 and quickly gained a substantial following. The online communication tool, which competes in the same space as Microsoft Teams, Facebook Workplace and Atlassian's HipChat, has five million daily active users – 1.5 million of which are paying users. As of January, Slack’s annual recurring revenue sat at $150 million.

In an interview last month, Stewart Butterfield, Slack co-founder and CEO, shot down the idea that an initial public offering would be in the company’s immediate future. Due to Slack’s rapid growth and the unpredictability it brings, an IPO “would be years away,” he said.

Update: Recode is also reporting today that Slack is in the middle of raising an additional $500 million at a $5 billion post-money valuation. The publication further notes that Microsoft, Google and Salesforce have also shown interest in acquiring the startup in the recent past.