Upwind Security has closed a $400 million Series C funding round at a $3.8 billion valuation, according to information shared directly with this writer. The financing marks a significant step forward for the cloud and AI security company as enterprises reassess how they protect increasingly complex infrastructure. The company, which reports having quadrupled its revenue in 2026, plans to use the new capital to accelerate product development and expand its go-to-market operations.

The round was led by Bessemer Venture Partners, with participation from Canapi Ventures and existing investors including Cyberstarts, Greylock Partners, Craft Ventures, Leaders Fund, Salesforce Ventures, TCV, Alta Park Capital, Penny Jar Capital, Cerca Partners, Swish Ventures and Picture Capital.

The new valuation represents a substantial increase from the $1.5 billion valuation Upwind secured in its Series B round in January 2026 .…