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This is a weekly feature that runs down the week’s top 10 announced funding rounds in the U.S. Check out last week’s biggest funding deal roundup here.

Startup investors were busily closing on big rounds this week, with AI and defense among their favored target sectors. The biggest financing went to Castelion, a defense tech startup developing a hypersonic missile. Other sizable rounds went to companies developing AI inference technology, a video-creation platform, data centers and voice-to-text tools.

1. Castelion, $800M, defense tech: Castelion, a defense tech startup developing a hypersonic strike missile, raised new Series C funding consisting of $800 million in equity capital along with $250 million in debt financing. JPMorgan Chase, Andreessen Horowitz and Carlyle led the equity financing, which set a $13 billion valuation for the Torrance, California-based company.

2. Etched, $700M, semiconductors: San Jose, California-based Etched, a developer of inference clusters to accelerate AI computing, secured $700 million in a new funding round led by Jane Street and joined by a long list of prominent investors. The financing set a $21 billion valuation for the 4-year-old company.

3. Higgsfield, $400M, AI video tools: AI video- and image-creation platform Higgsfield closed on $400 million in Series B financing at a $5.4 billion valuation. DST Global led the round for the San Francisco-based company, with the financing drawing at least 18 investors.

4. Groq, $350M, data centers: Groq, an operator of 13 data centers across the globe, pulled in $350 million in a new fundraise led by Disruptive, with planned participation from Nvidia.The fundraise, which values the San Francisco-based company at $3.5 billion, comes on the heels of a $650 million round in June.

5. Wispr Flow, $280M, voice-to-text AI: Wispr Flow, a provider of an AI-powered voice-to-text tool called Flow, picked up $280 million in Series B funding at a $2 billion valuation. Menlo Ventures led the financing, joined by a long list of new and existing investors.

6. Muon Space, $250M, satellites: Muon Space, a designer, builder and operator of satellite constellations, closed on $250 million in Series C funding led by Eclipse. The Mountain View, California-based company also recently opened a manufacturing facility in San Jose, California, designed to produce up to 500 satellites annually by 2027.

7. Also, $150M, micromobility: Also, a Rivian spinout that makes electric bikes and small four-wheeled micromobility vehicles, secured $150 million in Series D funding led by Prysm Capital. The Palo Alto, California-based startup said the financing will go in part toward accelerating development of its autonomous vehicle platform.

8. Velaura AI, $110M, AI computing: Velaura AI, a developer of AI compute infrastructure focused on ultra-low-power silicon and software technologies, picked up $110 million in Series A funding. Seligman Ventures led the financing, which set a valuation of over $1 billion for the Silicon Valley-based startup.

9. Rillet, $100M, agentic finance: Rillet, a developer of AI-powered enterprise resource planning tools, landed $100 million in Series C funding led by Iconiq Capital. The round, which sets a $1 billion valuation for the San Francisco company, is Rillet’s third financing in the past year.

10. Happy Health, $75M, sleep testing: Happy Health, and Austin-based developer of a ring device for diagnosis and treatment of sleep apnea, raised $75 million from Arch Venture Partners and OpenLoop.

Methodology

We tracked the largest announced rounds in the Crunchbase database that were raised by U.S.-based companies for the period of Aug. 15-21. Although most announced rounds are in the database, there may be a small time lag, as some rounds are reported late in the week.

Illustration: Dom Guzman

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