The venture capital landscape continues its robust activity, showcasing a dynamic period of innovation and significant investment across diverse, high-impact sectors. This past week, from March 28 to April 3, saw startup investors maintaining a busy dealmaking pace, with a collective $4.119 billion poured into ten U.S.-based companies. These substantial funding rounds highlight a strong appetite for transformative technologies, particularly in areas critical to national security, human well-being, sustainable energy, and digital resilience. The largest financings were strategically deployed into defense, wearables, energy, and cybersecurity, signaling market confidence in companies poised to reshape industries and address pressing global challenges.

Leading the charge this week was a monumental $1.75 billion Series D for Saronic, a pioneer in autonomous maritime defense. Other top recipients included innovators in fitness wearables, advanced nuclear energy, grid-scale battery technology, AI-driven cybersecurity, and the burgeoning space tech sector, among others. These investments underscore a venture capital ecosystem increasingly focused on deep tech, scalable infrastructure, and solutions with far-reaching societal and economic implications. For those tracking the largest startup funding deals in 2025 and beyond, the Crunchbase Megadeals Board remains an essential resource, curating over $100 million-plus venture deals to U.S.-based companies, reflecting the ongoing surge in significant capital commitments.

Here’s a closer look at the week’s top 10 announced funding rounds:

1. Saronic, $1.75 Billion, Autonomous Ships
Austin-based Saronic, a formidable player in defense technology, secured an astounding $1.75 billion in Series D funding. This round catapults its total funding to approximately $2.6 billion and establishes a formidable $9.25 billion valuation for the company, more than doubling its Series C valuation from 2025. Saronic specializes in the development of autonomous sea vessels, designed to enhance maritime capabilities for defense and security operations. These unmanned surface vessels (USVs) promise to revolutionize naval strategies by providing persistent surveillance, reconnaissance, and logistics support, reducing human risk and increasing operational efficiency. The investment, led by venture capital giant Kleiner Perkins, signifies a profound belief in Saronic’s potential to become a cornerstone of modern naval defense. The capital infusion will likely be channeled into accelerating research and development of next-generation autonomous systems, scaling manufacturing capabilities, and expanding its talent base of engineers and defense specialists, cementing its leadership in a rapidly evolving geopolitical landscape where maritime superiority is paramount.

2. Whoop, $575 Million, Fitness Wearables
Whoop, a Boston-based innovator in wearable fitness technology, successfully closed a $575 million Series G funding round, achieving an impressive $10.1 billion valuation. Whoop’s offering extends beyond simple activity tracking; its subscription platform meticulously tracks physiological data, including sleep, recovery, and daily strain, providing personalized insights and coaching to optimize performance and overall well-being. This significant investment, led by Collaborative Fund, underscores the growing consumer demand for sophisticated, data-driven health and wellness solutions. In a crowded market of smartwatches and fitness trackers, Whoop differentiates itself with a singular focus on holistic physiological insights, appealing to elite athletes and health-conscious individuals alike. The new capital will fuel further innovation in its sensor technology, enhance its AI-powered analytics, expand its global market reach, and potentially explore new applications in clinical or corporate wellness programs, solidifying its position as a leader in the personalized health tech space.

3. Valar Atomics, $450 Million, Nuclear Energy
El Segundo, California-based Valar Atomics, a nuclear energy startup reportedly backed by Oculus founder Palmer Luckey, raised fresh capital at a $2 billion valuation. This financing reportedly comprised $340 million in equity funding and an additional $110 million in debt. Valar Atomics is positioned at the forefront of a global resurgence in nuclear energy, driven by the urgent need for reliable, carbon-free power sources. While specific details on their technology remain under wraps, the substantial valuation suggests a focus on advanced nuclear designs, such as Small Modular Reactors (SMRs) or even next-generation fusion concepts, which promise safer, more efficient, and more rapidly deployable energy solutions compared to traditional nuclear plants. The blend of equity and debt funding is typical for capital-intensive infrastructure projects, indicating that Valar Atomics is moving beyond conceptualization towards tangible development and regulatory milestones. This investment highlights a growing investor confidence in nuclear power as a critical component of a sustainable energy future.

4. EnerVenue, $300 Million, Battery Technology
EnerVenue, a Fremont, California-based developer of grid-scale energy storage technology, announced a $300 million extension of its Series B preferred round, led by Full Vision Capital. Concurrently, the company appointed Henning Rath as its new chief executive officer, signaling a strategic push towards accelerated growth and commercialization. EnerVenue specializes in nickel-hydrogen batteries, a technology known for its exceptional durability, safety, wide operating temperature range, and long cycle life, making them ideal for demanding grid-scale applications. As the world transitions to renewable energy sources like solar and wind, robust and reliable energy storage solutions are paramount to ensure grid stability and manage intermittency. This funding will enable EnerVenue to significantly scale its manufacturing capacity, invest further in research and development to enhance battery performance, and aggressively pursue market opportunities for its long-duration storage solutions, thereby playing a crucial role in modernizing energy infrastructure.

5. Tenex.AI, $250 Million, Cybersecurity
Sarasota, Florida-based Tenex.AI, an AI-enabled cybersecurity startup, secured $250 million in Series B funding, led by Crosspoint Capital Partners. The company’s mission is to revolutionize cybersecurity by leveraging artificial intelligence to augment human capabilities, making security operations "ten times more efficient." In an era of increasingly sophisticated cyber threats and a persistent shortage of cybersecurity professionals, Tenex.AI’s approach is particularly timely. Their platform likely uses AI to automate threat detection, incident response, vulnerability management, and predictive analytics, freeing up human experts to focus on more complex strategic tasks. The funding will be instrumental in a significant hiring spree, with plans to onboard over 250 new employees, all of whom will be equipped with Tenex.AI’s proprietary AI technology. This investment underscores the critical role AI is playing in fortifying digital defenses and enhancing the productivity of security teams globally.

6. Also, $200 Million, Micromobility
Also, an electric mobility company that spun out of the electric vehicle giant Rivian, raised $200 million in a Series C round. This financing was backed by prominent investors including Greenoaks, DoorDash, and Prysm Capital. Based in Palo Alto, California, Also’s product lineup is diverse, encompassing electric bikes, small autonomous EVs specifically designed for deliveries, and associated gear. This strategic spin-out from Rivian leverages significant automotive engineering expertise to tackle the burgeoning micromobility market. The involvement of DoorDash as an investor is particularly notable, hinting at strategic partnerships and the potential integration of Also’s autonomous delivery EVs into last-mile logistics networks. This capital will allow Also to accelerate product development, scale manufacturing, expand its service offerings, and potentially enter new urban markets, capitalizing on the global shift towards sustainable, efficient, and increasingly autonomous urban transportation and delivery solutions.

7. Starcloud, $170 Million, Space Tech
Redmond, Washington-based Starcloud, a pioneering space infrastructure startup, secured $170 million in Series A funding, led by a powerful duo of Benchmark and EQT. This round propelled the company to a $1.1 billion valuation, making it the fastest Y Combinator alum to achieve unicorn status after its demo day, reaching this milestone in just 17 months. Starcloud is focused on an ambitious vision: building orbital data centers. This concept involves deploying computing infrastructure in space to process data closer to its source, reducing latency, enhancing security, and optimizing the efficiency of satellite constellations. The rapid ascent to unicorn status reflects intense investor excitement about the "new space" economy and the critical need for advanced data processing capabilities in orbit for applications ranging from Earth observation to defense and telecommunications. The funding will undoubtedly fuel aggressive R&D, prototype launches, and the recruitment of top talent in aerospace engineering, AI, and cloud computing.

8. ScaleOps, $130 Million, Cloud Infrastructure
New York-based ScaleOps, a cloud and AI infrastructure startup, landed $130 million in Series C funding. This round, led by Insight Partners, valued the four-year-old company at over $800 million. ScaleOps addresses the increasing complexity and cost associated with managing cloud resources and optimizing AI workloads. As enterprises scale their cloud adoption and deploy more AI-intensive applications, effective management of cloud spending, performance, and resource allocation becomes critical. ScaleOps likely provides a platform that offers FinOps (financial operations) capabilities, performance optimization, and automation for multi-cloud environments, helping businesses to derive maximum value from their cloud investments while controlling costs. The capital injection will enable ScaleOps to further develop its platform, expand its feature set to support more complex AI/ML operations, grow its sales and marketing efforts, and potentially explore international expansion, solidifying its position as a vital tool for modern digital enterprises.

9. Ambrosia Biosciences, $100 Million, Biotech
Boulder, Colorado-based Ambrosia Biosciences, a developer of next-generation oral therapeutics for obesity and related cardiometabolic diseases, picked up $100 million in Series B funding. The round saw strong participation from leading biotech and healthcare investors, including Blue Owl, Redmile Group, and Deep Track Capital. The global obesity epidemic and the rising incidence of cardiometabolic diseases represent a massive unmet medical need. Ambrosia Biosciences is focused on developing oral drug candidates, which offer significant advantages over injectables (like GLP-1 agonists such as Ozempic or Wegovy) in terms of patient convenience, adherence, and broader accessibility. This substantial funding will be crucial for advancing its lead therapeutic candidates through rigorous preclinical and clinical trial phases (Phase I, II, and potentially III), securing regulatory approvals, and expanding its research pipeline to tackle other cardiometabolic conditions, aiming to bring innovative, patient-friendly treatment options to market.

10. OpenFX, $94 Million, Money Transfer
OpenFX, a provider of a platform designed to facilitate seamless cross-border money transfers, secured $94 million in Series A funding. The round attracted a consortium of prominent investors, including Accel, Atomico, M13, Northzone, and Pantera Capital. OpenFX is operating in a highly competitive yet rapidly growing market, driven by globalization, increasing remittances, and the surge in cross-border e-commerce. Its platform aims to differentiate itself by offering faster, more cost-effective, and transparent alternatives to traditional banking systems for international transactions. The diverse investor group, which includes fintech specialists and those with exposure to blockchain/crypto (Pantera Capital), suggests OpenFX might leverage innovative technologies to streamline its operations. This capital will enable OpenFX to expand its global network, enhance its technological infrastructure, navigate complex international regulatory landscapes, introduce new features and currency corridors, and aggressively pursue market share in the lucrative cross-border payments sector.

Methodology
The funding rounds detailed above represent the largest announced deals tracked in the Crunchbase database for U.S.-based companies during the period of March 28-April 3. While efforts are made to capture all significant rounds, a small reporting lag may occur for some deals announced late in the week.

This past week’s robust funding activity, totaling over $4.1 billion across these top ten rounds, paints a clear picture of venture capital’s strategic focus. Investments in defense tech like Saronic highlight geopolitical realities and the imperative for advanced security solutions. Whoop’s significant round underscores the continued evolution of personalized health and wellness. The substantial capital flowing into Valar Atomics and EnerVenue signals a decisive shift towards sustainable, reliable, and innovative energy solutions. Furthermore, the strong backing for Tenex.AI reflects the critical role of AI in bolstering cybersecurity. From orbital data centers by Starcloud to next-gen biotech from Ambrosia Biosciences, these financings demonstrate an unwavering commitment to pioneering technologies that address complex challenges and define the future across multiple industries. The venture capital market remains dynamic, actively backing ventures poised for profound impact and exponential growth.