Upwind Security raises $250M at $1.5B valuation

Upwind Security has reached a $1.5 billion valuation following a $250 million Series B funding round. The investment follows a period of expansion for the cloud security startup, which posted 900% year-over-year revenue growth and doubled its customer base since its $100 million Series A in 2024.

The funding details include:

• Round size: $250 million
• Valuation: $1.5 billion
• Lead investor: Bessemer Venture Partners
• Other participants: Salesforce Ventures and Picture Capital

The company, founded four years ago, has built its business around runtime security, which involves prioritizing alerts and remediation efforts around threats and vulnerabilities in active services in real time. Amiram Shachar, co-founder and CEO of Upwind Security, describes this as an inside-out approach that uses internal signals like network requests and API traffic to provide context. This contrasts with traditional outside-in methods that scan environments externally. Shachar and his co-founders previously built and sold Spot.io, a cloud compute brokerage, to NetApp for around $450 million in 2020. Shachar noted that his experience at NetApp showed him how security teams often lacked critical context, flagging issues that were not real risks.

Building the platform involved significant early uncertainty. “Three years ago, we would spend hours asking ourselves if we were heading in the right direction, and 80% of the time, it felt like we weren’t,” said Shachar, co-founder and CEO. He recalled that the team constantly questioned whether the market needed their solution, whether it would be too difficult to integrate into larger systems, or if customers would adopt it. He explained that inside-out security is necessary to solve problems associated with ephemeral infrastructure—such as containers, serverless workloads, and AI agents—because these systems cannot be mapped from the outside.

Upwind’s customer base includes Siemens, Peloton, Roku, Wix, Nextdoor, and Nubank. While the company initially focused on its core markets in the U.S., U.K., and Israel, it has since expanded into Australia, India, Singapore, and Japan. With the fresh Series B capital, Upwind plans to invest in its AI security capabilities within its core cloud security platform. The startup also plans to extend its approach closer to developers to help prevent misconfigurations before they reach production.

Why it matters

Upwind’s growth and valuation highlight the market’s shift toward inside-out runtime security, which provides deeper context for cloud environments compared to traditional external scanning methods.