Upwind Series C Raises $400M at $3.8B Valuation, Bessemer Leads

Upwind, a cloud and AI security startup, announced on 28 October 2026 that it raised a $400 million Series C led by Bessemer Venture Partners. The round followed a $250 million Series B in January 2026. SiliconANGLE reported a $3.8 billion valuation for the round.

How much did Upwind raise in its Series C?

Upwind raised $400 million in a Series C, according to the company's announcement on 28 October 2026. SiliconANGLE names Bessemer Venture Partners as the lead. The Next Web reported the same round size and lead on the same day. The company's announcement also says the round came less than nine months after its $250 million Series B.

The round is larger than the figure first reported. SaasRise reported a $300 million Series C on 4 September 2026, and Stock Analysis listed the latest round at $300 million as of 3 September 2026. SiliconANGLE reported that the early September figure was $300 million and that Upwind took in an additional $100 million by the time the round closed.

What is Upwind's valuation, and who set it?

The $3.8 billion valuation is self-reported. It appears in the coverage of the announcement, and no independent filing has been cited for it. SiliconANGLE and The Next Web both attribute it to the announcement.

Measured against the January Series B, the valuation rose from $1.5 billion to $3.8 billion, about 2.5 times, between January and October 2026. That step-up is computed from the two reported valuations. Neither source gives a price per share or a pre-money figure, so the calculation cannot be checked further.

Why did the round grow from $300 million to $400 million?

The coverage describes a larger close, not a change in lead investor. SiliconANGLE says early reports had the round at $300 million and that Upwind added another $100 million before closing.

For a reader comparing reports, the distinction matters. The September figure and the October figure describe the same round at different stages, not two rounds. Reports from early September already carried the $3.8 billion valuation, according to SaasRise, so the valuation did not change between the two reports as far as these sources show. Read together, the two reports describe one round at two stages, and the later figure is the one the company has announced.

What does Upwind do?

Upwind describes a cloud and AI security platform that collects runtime data from cloud workloads, APIs and AI agents. The company says that data gives security, development and DevOps teams one view of their cloud and AI systems. The Next Web summarizes the product as runtime security for these environments.

According to the company, the platform collects telemetry from cloud workloads through the Linux eBPF subsystem without invasive kernel modifications, refreshing the data every 30 seconds. It uses specialized AI agents to investigate, confirm and fix alerts, which the company says leaves human staff free to focus on judgment and response. Upwind's announcement describes the new funding as money for product development and a broader go-to-market push.

Who founded Upwind?

Upwind was founded in 2022. Co-founder and chief executive Amiram Shachar started the company with former colleagues from Spot, a cloud infrastructure optimization startup that NetApp acquired in 2020. SiliconANGLE quotes Shachar saying the platform was built to "unify those signals."

How fast is Upwind's revenue growing?

Upwind says its revenue has quadrupled in 2026 so far. SiliconANGLE reported the claim as part of the announcement, and The Next Web repeated it. Both attribute the figure to the company.

The claim has no dollar base. Neither source gives a revenue number, a start date for the quadrupling, or an annual run rate, so growth can be reported as a multiple but not as an absolute amount. This is the main limit on reading the valuation: $3.8 billion relative to revenue cannot be calculated from the public coverage.

How much has Upwind raised in total?

SiliconANGLE reports that investors have put about $830 million into Upwind in total. That figure comes from one source, so treat it as reported, not confirmed.

Adding the two rounds in the public coverage gives $650 million: the $250 million Series B and the $400 million Series C. The remaining amount would come from rounds that the coverage does not itemize. Readers should not add the $830 million total to the Series C figure, because the total already includes it. The two numbers answer different questions: the round size is what this announcement added, and the total is what investors have put in over the company's life.

What's still unclear?

• Headquarters. Cyberstarts lists San Francisco, California, with no country. This article reports that listing only.
• Lead investors. SiliconANGLE names Bessemer as the sole lead. SaasRise's September report named Bessemer and TCV together. The later coverage does not repeat TCV.
• Valuation. $3.8 billion is the company's figure, and no primary document in this coverage confirms it independently.
• Revenue. "Quadrupled" has no base, start date or dollar amount in the reports.
• Total funding. The $830 million total appears in one source.
• Weakest point of the argument. Almost all the numbers in this story come from the company's announcement and the first day of coverage. Until a filing or a later report confirms them, the valuation and growth figures are company claims.