Upwind Security, a cloud and artificial-intelligence security startup, has closed a $400 million Series C round at a $3.8 billion valuation led by Bessemer Venture Partners, a notable vote of confidence from venture investors even as public technology stocks wobbled last week on AI-bubble fears. The round, first detailed in trade coverage of the financing, comes after Upwind reportedly turned down a buyout offer from Datadog valued at roughly the same $3.8 billion — a no-premium offer that would have matched its already-private valuation rather than rewarding shareholders for selling.
The new valuation is more than four times what Upwind was worth at its previous raise in December 2024, when it closed a $100 million round at roughly $900 million. Total funding now exceeds $800 million, and the company says its revenue roughly quadrupled over the course of 2026. Upwind builds a runtime and cloud-workload protection platform that competes with offerings from Wiz and Datadog's own security products, aiming to detect threats as they happen inside live cloud environments rather than relying solely on static configuration scans.
The decision to raise private capital instead of selling is unusual in a sector where many venture-backed security startups are eventually absorbed by larger platform players looking to bolt on new capabilities. It signals that Upwind's investors believe the company can grow faster as an independent business than it would inside Datadog, and it keeps alive the possibility of a larger exit — an IPO or a higher-priced acquisition — further down the road.
The round lands at a moment of intense investor appetite for cybersecurity and AI-adjacent startups even as broader markets wobble: it was announced the same week Oracle moved to raise $20 billion in debt and stock to fund its own AI infrastructure buildout, and as the Nasdaq posted its worst October since early 2025. For now, Upwind's bet is that demand for cloud-security tools built for an AI-heavy computing environment will keep outrunning the market's broader jitters — and that staying independent, rather than selling to a bigger rival, is the better way to capture that growth.
