Upwind raises $400M Series C at $3.8B valuation for AI cloud security

Upwind closed a $400 million Series C led by Bessemer Venture Partners at a $3.8 billion post-money valuation, according to CEO Amiram Shachar. The round came less than nine months after a $250 million Series B. Canapi Ventures participated alongside Cyberstarts, Greylock Partners, Craft Ventures, Leaders Fund, Salesforce Ventures, TCV and several smaller backers. The company says its revenue quadrupled in 2026, but no absolute ARR figure appeared in the coverage reviewed. The company sells a cloud security platform that uses runtime intelligence to show which workloads actually execute, rather than what a static scan flagged. It is extending that approach to AI systems, a category where security vendors compete for budget as enterprises put models and agents into production. For founders building AI products, the round shows investors will pay for controls that watch live behavior, not only code. Teams shipping agents should expect buyers to ask how runtime exposure is monitored and who reviews it.