The Week’s 10 Biggest Funding Rounds: Defense Tech, AI Tools And Infrastructure Lead The Way
The biggest financing of the week 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.
In the week of August 15-21, 2026, the largest U.S.-based startup funding rounds centered around defense technology, artificial intelligence, semiconductors, data centers, voice-to-text tools, satellite technology, micromobility, AI computing infrastructure, agentic finance, and sleep testing. Castelion secured $800 million in Series C funding for its hypersonic missile development, while Etched raised $700 million for AI inference clusters to accelerate computing.
Higgsfield, an AI video and image creation platform, received $400 million in Series B financing, while Groq, a data center operator, closed on $350 million to value the company at $3.5 billion. Wispr Flow, a voice-to-text AI tool provider, raised $280 million in Series B funding, and Muon Space, a satellite constellation designer, secured $250 million in Series C financing.
Also, a Rivian spinout making electric bikes and micromobility vehicles, received $150 million in Series D funding, and Velaura AI, focused on ultra-low-power AI compute infrastructure, closed on $110 million in Series A funding. Rillet, which develops AI-powered ERP tools, landed $100 million in Series C funding, and Austin-based Happy Health, a sleep apnea diagnosis and treatment device developer, raised $75 million from investors.
Written by urgent.news from Crunchbase News's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
