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Want to keep track of the largest startup funding deals in 2025 with our curated list of $100 million-plus venture deals to U.S.-based companies? Check out The ½ûÂþÌìÌà Megadeals Board.

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.

This week, just half of the top 10 rounds crossed the $100 million mark, which is somewhat unusual in this high-flying era for venture megarounds. Nonetheless some large checks did get written, led by ’s $5 billion investment and partnership deal with . Other sizable rounds went to companies in sectors including aviation autonomy, vision therapy and AI analytics.

1. , $5B, foundational AI: AI giant Anthropic that Amazon is investing $5 billion in the company, with up to an additional $20 billion in the future. Previously, Amazon had invested $8 billion in the San Francisco-based company. The latest financing also includes a partnership with Amazon for training and deploying Anthropic’s AI assistant Claude.

2. , $160M, autonomous aircraft: Reliable Robotics, a developer of autonomous aircraft systems, raised $160 million in fresh financing led by . The 9-year-old, Mountain View, California-based company markets its technology for both commercial and defense aviation.

3. , $125M, vision therapy: San Diego-based Ray Therapeutics, a biotech startup focused on vision restoration therapies, secured $125 million in Series B funding led by . Founded in 2021, Ray has raised $247 million in venture and grant funding to date, per .

4. , $120M, AI analytics: Omni, developer of an AI-enabled analytics platform, closed on $120 million in Series C funding led by . The financing set a $1.5 billion valuation for the 4-year-old, San Francisco-based company.

5. , $106M, biotech: Framingham, Massachusetts-based Tortugas Neurosciences, neurology-focused biotech startup, scooped up $106 million in Series A funding. Founding investor co-led the round alongside and .

6. , $80M, medtech: AcuityMD, an AI-enabled data and research platform for medtech industry customers, picked up $80 million in Series C investment. led the funding for the 7-year-old, Boston-based company.

7. , $75M, foundational AI: that it purchased $75 million worth of San Francisco-based OpenAI’s common stock. The shares are owned by Robinhood Ventures Fund I, a publicly traded fund that provides investors exposure to a curated portfolio of private companies.

8. , $60M, workflow orchestration: Orkes, developer of an AI-enabled software workflow orchestration platform, secured $60 million in Series B funding. led the financing for the 5-year-old, Silicon Valley-based startup.

9. , $50M, health tech: Courier Health, a developer of tools to improve patient experience for people with chronic conditions or rare diseases, closed on $50 million in Series B funding. led the financing for the New York-based company.

10. , $50M, biotech: Cambridge, Massachusetts-based Serif Bio­med­i­cines, a biotech­ startup focused on Mod­i­fied DNA as a new class of med­i­cines, launched with $50 million in initial funding from .

Methodology

We tracked the largest announced rounds in the ½ûÂþÌìÌà database that were raised by U.S.-based companies for the period of April 18-24. Although most announced rounds are represented in the database, there could be a small time lag as some rounds are reported late in the week.

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