As the venture capital landscape in 2025 continues to evolve, this past week showcased a vibrant and strategically significant period for startup funding, even without the headline-grabbing multi-billion-dollar rounds. The diversity of innovation attracting substantial capital was remarkable, spanning critical sectors from cutting-edge semiconductors to the future of aerospace, advanced biotechnology, and crucial AI infrastructure. This week’s top 10 list highlights the enduring investor confidence in deep technology, healthcare breakthroughs, and solutions addressing complex global challenges, with SiFive leading the pack with a formidable $400 million for its custom chip designs.

For those tracking the most substantial startup funding deals to U.S.-based companies in 2025, the Crunchbase Megadeals Board remains an indispensable resource. This weekly rundown serves as a crucial barometer for the health and direction of the venture ecosystem, following up on last week’s significant rounds across AI, defense, wearables, and energy. This week’s narrative underscores a robust appetite for innovation that promises to redefine industries and address pressing societal needs.

1. SiFive, $400M, Semiconductors
San Mateo, California-based SiFive emerged as the week’s funding champion, securing a staggering $400 million in a Series G round led by Atreides Management. This substantial investment underscores the growing confidence in SiFive’s mission to disrupt the semiconductor industry’s traditional landscape. SiFive is at the forefront of the open-standard RISC-V architecture, providing the foundational blueprints, or intellectual property (IP) cores, that companies like Alphabet leverage to craft their own highly specialized internal chip designs. This approach offers a compelling alternative to proprietary standards, such as those historically dominated by Arm Holdings, by granting greater flexibility, customization, and cost-efficiency to chip developers. The demand for custom silicon is skyrocketing, driven by the insatiable needs of artificial intelligence, cloud computing, and specialized edge devices, where off-the-shelf chips often fall short. SiFive’s CEO, Patrick Little, indicated that this significant raise is anticipated to be the company’s final funding round before it pursues an initial public offering (IPO), signaling a mature and confident trajectory towards public markets, though no specific timeline was provided. This move solidifies SiFive’s position as a critical enabler in the next generation of computing.

2. Hermeus, $200M, Aviation
In the dynamic aerospace sector, El Segundo, California-based Hermeus soared with $200 million in equity funding, spearheaded by Khosla Ventures, complemented by an additional $150 million in debt financing. This combined capital injection propelled Hermeus to a coveted unicorn valuation of $1 billion, reflecting the immense potential and strategic importance of its endeavors. Hermeus is developing autonomous military aircraft designed to achieve unprecedented speeds, aiming for Mach 5 and beyond. Their vision centers on creating the fastest uncrewed defense aircraft, leveraging advanced propulsion systems and aerodynamic designs. The investor syndicate is particularly noteworthy, including Socium Ventures, RTX Ventures (the corporate venture arm of aerospace and defense giant RTX), Karman Ventures, Founders Fund, IQT (the venture capital firm funded by the CIA and other intelligence agencies), and Cox Enterprises. This diverse backing highlights both the commercial and national security implications of Hermeus’s technology, positioning it as a key player in the future of hypersonic flight and defense capabilities. The capital will be instrumental in accelerating the development and testing of their groundbreaking prototypes.

3. Sidewinder Therapeutics, $137M, Biotechnology
San Diego-based Sidewinder Therapeutics demonstrated the continued strength of biotech innovation, closing a $137 million Series B round. The investment was co-led by Frazier Life Sciences, a specialist in healthcare venture capital, and Novartis Venture Fund, the corporate venture arm of the pharmaceutical giant Novartis. Sidewinder is focused on a critical frontier in cancer treatment: developing next-generation antibody-drug conjugates (ADCs). These sophisticated cancer drugs are engineered to act as "guided missiles," utilizing highly specific antibodies to precisely deliver potent toxic payloads directly into tumor cells, thereby minimizing collateral damage to healthy tissues. This targeted approach represents a significant leap forward from conventional chemotherapy, which often comes with severe side effects. Sidewinder’s focus on difficult-to-treat tumors indicates its ambition to tackle some of oncology’s most persistent challenges. The company stated that this new funding will be pivotal in advancing its lead drug candidates through preclinical development and into crucial human clinical trials, a critical step towards bringing these innovative therapies to patients.

4. Aria Networks, $125M, AI Infrastructure
Palo Alto, California-based Aria Networks secured $125 million in a Series A funding round led by Sutter Hill Ventures, underscoring the escalating importance of robust infrastructure for the burgeoning artificial intelligence sector. As AI models grow in complexity and data demands skyrocket, the underlying data center networks face unprecedented strain. Aria Networks addresses this challenge by developing an AI-driven networking platform designed to intelligently monitor, analyze, and optimize data center performance in real-time. This technology is crucial for ensuring the high bandwidth, low latency, and reliability required for AI training, inference, and large-scale cloud operations. By leveraging AI to manage network traffic, predict bottlenecks, and dynamically reconfigure resources, Aria Networks helps cloud providers and large enterprises maximize efficiency, reduce operational costs, and prevent system failures. Sutter Hill Ventures’ leadership in this round signals a strong belief in Aria’s ability to become a foundational technology for the next generation of AI-powered computing environments.

5. Starfish Space, $111.7M, Aerospace
Seattle-based Starfish Space garnered $111.7 million in a Series B round led by Activate Capital Partners, Point72 Ventures, and Shield Capital, highlighting the urgent need for sustainable space operations. Starfish Space is pioneering the development and manufacturing of autonomous space vehicles capable of performing crucial in-orbit servicing (IOS) missions. Their innovative spacecraft are designed to dock with existing satellites, offering services such as refueling, repositioning, extending operational lifespans, and even performing critical repairs. Beyond maintenance, Starfish also addresses the escalating problem of space debris by developing capabilities to de-orbit defunct satellites and remove hazardous orbital junk. With the proliferation of satellite constellations, the long-term sustainability and safety of space are paramount. Starfish Space’s technology offers a viable solution for prolonging asset life, improving orbital efficiency, and mitigating environmental risks in space, making it a vital player in securing the future of the global space economy and critical national security assets in orbit.

6. (tied) Stipple Bio, $100M, Biotechnology
Cambridge, Massachusetts-based Stipple Bio announced a $100 million Series A round to advance its precision cancer therapies. The round was co-led by prominent investors a16z Bio+Health, Nextech Invest (an oncology-focused venture firm), and RA Capital Management, signaling strong confidence in Stipple’s innovative approach. Stipple Bio is dedicated to developing highly targeted cancer treatments that are designed to selectively attack cancer cells while minimizing damage to healthy tissue. This precision oncology approach is critical for improving patient outcomes and reducing the debilitating side effects often associated with conventional cancer treatments. While specific therapeutic modalities were not disclosed, such a substantial Series A suggests Stipple is employing novel biological or small-molecule strategies to achieve unprecedented specificity. The funding will accelerate Stipple’s research and development efforts, pushing its lead programs closer to clinical validation and offering hope for more effective and tolerable cancer therapies in the future.

7. (tied) Chapter, $100M, Health Insurance
New York-based Chapter raised $100 million in a Series E round led by Generation Investment Management, a firm known for its focus on sustainable and impactful investments. Chapter operates a crucial Medicare navigation platform, providing expert advisory services to seniors seeking to understand and select the most suitable health coverage options. Navigating the complexities of Medicare plans can be overwhelming, leading to suboptimal choices and unnecessary costs for millions of Americans. Chapter simplifies this intricate process through a combination of technology and human expertise, offering personalized guidance that helps seniors optimize their health benefits and financial savings. With the rapidly aging population, the market for such services is vast and growing, making Chapter a vital resource for ensuring equitable access to comprehensive healthcare. Other notable investors in this round included XYZ Venture Capital, Maverick Ventures, and 8VC, all recognizing the immense potential in modernizing and humanizing the health insurance enrollment experience.

8. Modus, $85M, Fintech
Philadelphia-based Modus secured an impressive $85 million in a combined seed and Series A round led by Lightspeed Venture Partners, with participation from Comma Capital and influential investor Garry Tan. Modus is poised to revolutionize the traditional audit industry by positioning itself as a tech-enabled audit platform. The company’s strategy involves acquiring existing CPA firms and then equipping them with advanced, AI-driven audit tools. This hybrid approach aims to address the long-standing challenges within the auditing profession, including efficiency gaps, talent shortages, and the increasing complexity of financial regulations. By integrating AI, Modus intends to enhance the quality and accuracy of audits through automated data analysis, anomaly detection, and predictive insights, allowing human auditors to focus on higher-value tasks and critical judgment. This investment highlights a broader trend of applying cutting-edge technology to modernize established, often slow-to-adapt, professional services, promising more robust and reliable financial oversight.

9. Endovascular Engineering, $80M, Medical Devices
Menlo Park, California-based Endovascular Engineering, also known as E2, successfully closed an $80 million Series C funding round, co-led by Gilde Healthcare and Norwest Venture Partners. This significant capital injection will fuel the commercialization and further development of E2’s innovative HÄLO device, which received crucial FDA clearance in December. The HÄLO device is designed for the treatment of venous thromboembolism (VTE), a serious condition encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE), which can be life-threatening. E2’s technology represents a significant advancement in interventional medicine, offering a potentially less invasive and more effective solution for removing blood clots. The FDA clearance is a testament to the device’s safety and efficacy, paving the way for its adoption in clinical settings. This funding will enable E2 to scale its manufacturing, expand its market reach, and conduct further studies to demonstrate the HÄLO device’s long-term benefits for patients suffering from VTE.

10. Life Biosciences, $80M, Biotechnology
Boston-based Life Biosciences announced an $80 million Series D funding round, dedicated to its ambitious goal of developing drugs to promote longevity and treat age-related diseases. While the specific investors for this round were not disclosed, the company has previously attracted backing from specialized funds like Longevitytech.fund, along with Alpha Wave Ventures, LeFrak, Apple Core Holdings, and George Godula. Life Biosciences is a prominent player in the rapidly expanding field of geroscience, focusing on understanding and intervening in the fundamental biological processes of aging. The company plans to use this new capital to advance human trials of its cellular rejuvenation therapy, designated ER-100. This therapy aims to make older, damaged cells function as if they were younger, potentially reversing aspects of cellular aging. If successful, such therapies could revolutionize medicine by not only extending healthy human lifespan but also by preventing or treating a wide array of age-related conditions, from neurodegenerative diseases to cardiovascular ailments.

Methodology
This comprehensive overview tracked the largest announced funding rounds within the Crunchbase database for U.S.-based companies during the period of April 4-10, 2025. While Crunchbase strives for real-time accuracy, a slight time lag may occur as some rounds are reported later in the week.

Illustration: Dom Guzman

This week’s funding landscape clearly indicates a strong and diversified venture capital market, particularly vibrant in deep tech, life sciences, and critical infrastructure. The emphasis on innovative solutions for complex challenges, from open-source chip design to space sustainability and cellular rejuvenation, suggests a forward-looking investment strategy poised to shape the technological and medical advancements of the coming decade.