The US startup funding market remained red-hot this week as a wave of companies secured significant capital injections. According to Crunchbase data, 10 US-based companies closed funding rounds exceeding $100 million between March 28 and April 3, spanning high-growth sectors from defense tech to biotechnology.
Austin-based defense tech startup Saronic topped this week’s list. The company announced a $1.75 billion Series D round led by Kleiner Perkins. The raise brings Saronic’s valuation to $9.25 billion, doubling its valuation since its Series C round in 2025. Focused on the development of autonomous maritime vessels, the company has now raised a total of $2.6 billion to date.
Tech and Energy Sectors See Strong Gains
Wearable tech firm Whoop followed closely, securing $575 million in Series G funding and pushing its valuation to $10.1 billion. Led by Collaborative Fund, the round will enable the Boston-based company to further expand its physiological data-tracking platform.
Energy and infrastructure also attracted significant interest. California-based nuclear energy startup Valar Atomics raised $450 million through a mix of equity and debt, reaching a $2 billion valuation. Meanwhile, grid-scale energy storage developer EnerVenue announced a $300 million extension to its Series B round and appointed Henning Rath as its new CEO.
In the AI and cloud infrastructure space, Florida-based Tenex.AI secured $250 million in Series B funding. The company plans to use the capital to bolster its talent pool and enhance operational efficiency through its AI-driven cybersecurity technology. Cloud and AI infrastructure startup ScaleOps also closed a $130 million Series C round led by Insight Partners, pushing its valuation past the $800 million mark.
Rounding out this week’s list, Also—an electric mobility spinoff from Rivian—raised $200 million to develop its micro-mobility products. Space infrastructure startup Starcloud secured $170 million in Series A funding at a $1.1 billion valuation, becoming one of the fastest companies in Y Combinator history to reach unicorn status. Additionally, biotech firm Ambrosia Biosciences and cross-border payment platform OpenFX closed rounds of $100 million and $94 million, respectively.
