Upwind Security, a cloud and artificial-intelligence security startup, raised $400 million in a Series C round that values the company at $3.8 billion, more than double its price from nine months ago.
Bessemer Venture Partners led the round, with Canapi Ventures joining as a new investor. Existing backers including Cyberstarts, Greylock Partners, Craft Ventures, Salesforce Ventures and TCV also participated. Upwind, founded in 2022 and run by Israeli entrepreneur Amiram Shachar, was valued at $1.5 billion in its Series B in January, and has now raised more than $800 million in total.
Walking away from a buyer
The financing nearly took a different shape. Observability software company Datadog Inc. approached Upwind about an acquisition while the round was being assembled, according to a person familiar with the matter cited in a published report. The suitor did not offer a premium to the $3.8 billion valuation venture investors were prepared to pay, and Upwind chose to remain independent, the person said.
The episode reflects how hot demand has become for security software tied to AI. Large incumbents have paid up for cloud security assets over the past two years, and late-stage investors have been willing to match strategic bids for fast-growing companies.
Security inside live systems
Upwind’s platform monitors what is actually running inside customers’ cloud environments, rather than relying mainly on periodic scans, and uses that context to rank exposures and spot attacks across workloads, application interfaces and autonomous AI agents. It supports the major public clouds and sells through Amazon’s cloud marketplace. Customers include Siemens, Roku, Carvana and Nubank.
The company said revenue has roughly quadrupled in 2026 and that the new capital will go to product development and expanding its enterprise sales operation.
