Upwind, a cloud security platform specializing in runtime intelligence, has closed a $400 million Series C funding round that values the company at $3.8 billion. The official announcement on October 28, 2026, follows reports that the startup walked away from an acquisition offer from Datadog valued at approximately $4 billion.
The decision to remain independent and pursue a private valuation nearly identical to the reported buyout offer signals a significant bet on the company’s long-term growth. Led by Bessemer Venture Partners, the funding round also saw participation from new investor Canapi Ventures and existing backers including Greylock, Cyberstarts, Craft Ventures, Salesforce Ventures, and TCV.
Upwind’s financial performance appears to have provided the leverage for this independence. The company’s revenue quadrupled over the course of 2026, with annual recurring revenue (ARR) projected to reach nearly $100 million by the end of the year. This growth trajectory reflects a broader shift in the security market toward “runtime” data, which monitors active cloud environments rather than relying on periodic static scans.
The Runtime-First Strategy
Upwind’s platform distinguishes itself by using runtime data to identify exposures and detect attacks as they happen. While traditional cloud security tools often focus on identifying vulnerabilities in code before it is deployed, Upwind monitors the live environment to provide context on which risks are actually exploitable in real-time.
Co-founder and CEO Amiram Shachar is a repeat entrepreneur in the infrastructure space, having previously sold Spot.io to NetApp for $450 million in 2020. According to the company’s official Series C announcement, the new capital will be used to accelerate product development and expand its workforce.
As part of the funding milestone, Upwind introduced a suite of specialized AI security agents designed to automate complex tasks:
- Blue Agents: Focused on automated threat investigation and response.
- Red Agents: Designed for continuous, automated penetration testing and risk assessment.
- Green Agents: Built to manage remediation and ensure security hygiene across cloud fleets.
Market Context and the Datadog Offer
The rejection of the Datadog offer mirrors a recent trend among high-growth cybersecurity firms choosing to stay private despite multi-billion dollar exit opportunities.
For Upwind, the $4 billion Datadog offer represented a significant premium. By securing a $3.8 billion private valuation just weeks later, Upwind has effectively replaced the acquisition capital with investment capital while retaining control over its roadmap.
The move positions Upwind to compete more directly with established cloud security posture management (CSPM) and detection vendors. The company intends to use the $400 million to deepen its footprint in the AI-security sector, focusing on the protection of large-scale AI models and the infrastructure that supports them.
