Cloud cybersecurity startup Upwind Security has raised $400 million in Series C funding at a $3.8 billion valuation, more than doubling its valuation in nine months as demand for AI and cloud infrastructure protection accelerates.
The round was led by Bessemer Venture Partners, with participation from Canapi Ventures and existing backers including Greylock Partners, Cyberstarts, Craft Ventures, Salesforce Ventures and TCV.
The investment brings Upwind's total funding to more than $800 million since its founding in 2022.
The company says its revenue has quadrupled during 2026, although it has not disclosed its full audited financial results.
Why Cloud Security Is Changing
Traditional cybersecurity tools frequently identify vulnerabilities by scanning infrastructure configurations, application dependencies and access permissions.
But identifying a potential vulnerability is not the same as determining whether attackers can exploit it.
A cloud environment might contain thousands of security findings, many of which present little immediate danger.
Security teams must determine which problems represent genuine threats and which are unlikely to result in an attack.
Upwind focuses on what happens inside cloud environments while applications are running.
Its platform monitors workloads, network connections, application activity and APIs to identify exploitable vulnerabilities and detect suspicious behavior.
The approach, known as runtime security, aims to give organizations a more accurate picture of their actual exposure.
Protecting AI Agents
The increasing use of autonomous AI agents creates another security challenge.
Unlike conventional software, AI agents can independently execute tasks, access sensitive information and interact with multiple enterprise systems.
An agent with excessive permissions could expose confidential data or make unintended changes to infrastructure.
Upwind is expanding its platform to monitor agent behavior alongside the applications and infrastructure those agents interact with.
The company is also developing specialized AI agents to investigate threats, validate vulnerabilities and assist with remediation.
Its Blue Agent investigates security events, Red Agent tests whether vulnerabilities can actually be exploited, and Green Agent identifies ways to resolve security findings.
The broader strategy is to move cybersecurity from generating alerts toward helping organizations investigate and resolve threats.
Who Founded Upwind?
Upwind was founded by Amiram Shachar and a team of cloud infrastructure specialists who previously developed Spot.io.
Spot.io helped businesses optimize cloud computing costs and was acquired by NetApp in 2020.
Shachar's experience informed Upwind's focus on cloud infrastructure and the operational challenges faced by engineering teams.
The company now serves organizations including Siemens, Roku, Nubank, Supabase and ClickUp.
The Valuation and Acquisition Question
Upwind's latest financing values the business at $3.8 billion, compared with the $1.5 billion valuation announced alongside its Series B earlier in 2026.
According to TechCrunch, Datadog explored acquiring Upwind, but the company ultimately chose to remain independent. The report also cited estimates that Upwind could finish 2026 with approximately $90 million in annualized recurring revenue.
Those financial estimates have not been publicly confirmed by Upwind.
If realized, they would imply a valuation exceeding 40 times annualized recurring revenue, illustrating the expectations investors are placing on rapidly growing cybersecurity companies.
What Comes Next?
Upwind plans to use the financing to expand its engineering organization, develop additional security capabilities and grow its enterprise customer base.
Its opportunity is significant as companies deploy more AI applications and autonomous agents across cloud infrastructure.
However, established cybersecurity vendors are also developing runtime monitoring and AI security products.
Upwind must demonstrate that its approach offers sufficiently better threat detection, operational efficiency and remediation to justify its premium positioning.
The next challenge is converting rapid growth into a durable position in the increasingly competitive cloud security market.