AI Security Startup Upwind Raises $400M at $3.8B Valuation

In brief

• Upwind Security raised a $400 million Series C led by Bessemer Venture Partners at a $3.8 billion valuation, up from $1.5 billion in January.
• The company says revenue quadrupled in 2026 but has not disclosed dollar figures.
• The money will fund AI sensors for endpoints, scanners for AI agents and their skills, and expansion into identity, data and AI security.

Upwind Security raised $400 million in a Series C round at a $3.8 billion valuation, the cloud and AI security company announced Wednesday. Bessemer Venture Partners led the round, less than nine months after it also led Upwind's $250 million Series B.

Canapi Ventures joined as a new investor, and every existing backer returned, pouring even more money into the startop. Upwind said it will put the money toward product and engineering growth.

“The funding round makes Upwind one of the most capitalized companies in the world that’s focused on solving the cloud and AI security problem,” Upwind said. “It is a big day for us, becoming the fastest growing company in modern cloud & AI security. But, it is still a small milestone in our journey.”

Upwind says revenue quadrupled in 2026, though its press release gives no dollar figures. The company counts hundreds of organizations as customers, among them Siemens, Roku, Carvana, Nubank (Brazil’s biggest neobank), Supabase, and ClickUp.