The 10 Largest US Funding Rounds of December 2025

Armed with some data from our friends at CrunchBase, I broke down the largest US startup funding rounds from December 2025. I have included some additional information such as industry, company description, round type, founders, and total equity funding raised to further the analysis.

10. HawkEye 360 $150.0M
Round: Series E
Description: Herndon-based HawkEye 360 detects, geolocates, and characterizes various RF signals using its satellite constellation in low Earth orbit. Founded by Charles Clancy, Chris DeMay, John Serafini, and Robert McGwier in 2015, HawkEye 360 has now raised a total of $522.3M in total equity funding and is backed by Insight Partners, Alumni Ventures, BlackRock, Lockheed Martin Ventures, and Adage Capital Management.
Investors in the round: Andreessen Horowitz, BlackRock, Blackstone Group, Coatue, Fidelity, GIC, Infinitum, Insight Partners, J.P. Morgan Asset Management, MGX, New Enterprise Associates, Ontario Teachers’ Pension Plan, Robinhood Ventures, Temasek Holdings, Thrive Capital, T. Rowe Price, Winslow Capital
Industry: Aerospace, Analytics, Artificial Intelligence (AI), Navigation, Satellite Communication, Wireless
Founders: Charles Clancy, Chris DeMay, John Serafini, Robert McGwier
Founding year: 2015
Total equity funding raised: $522.3M

9. Harness $200.0M
Round: Series E
Description: San Francisco-based Harness provides a software delivery platform that helps engineering teams build, deploy, and operate applications through a set of tools. Founded by Jyoti Bansal and Rishi Singh in 2017, Harness has now raised a total of $570.0M in total equity funding and is backed by Menlo Ventures, Gaingels, IVP, Norwest, and Battery Ventures.
Investors in the round: Carrick Capital Partners, Kohlberg Kravis Roberts, Sixth Street Growth, Ten Eleven Ventures
Industry: Artificial Intelligence (AI), Developer Tools, DevOps, Productivity Tools, SaaS
Founders: Jyoti Bansal, Rishi Singh
Founding year: 2017
Total equity funding raised: $570.0M

8. Tebra $250.0M
Round: Venture
Description: Corona Del Mar-based Tebra provide independent healthcare practices with digital tools and support to thrive in a new era of healthcare. Founded by Dan Rodrigues, Luke Kervin, and Travis Schneider in 2021, Tebra has now raised a total of $387.0M in total equity funding and is backed by Vivo Capital, JP Morgan, StepStone Group, Transformation Capital, and Hildred Capital.
Investors in the round: Altimeter Capital, Andreessen Horowitz, Avenir Group, BlueYard Capital, Cantos, Champion Hill Ventures, First In, General Catalyst, Interlagos Capital, Lavrock Ventures, Lightspeed Venture Partners, Silent Ventures, Space.VC, Valor Equity Partners
Industry: Electronic Health Record (EHR), Health Care, Medical
Founders: Dan Rodrigues, Luke Kervin, Travis Schneider
Founding year: 2021
Total equity funding raised: $387.0M

8. K2 Space $250.0M
Round: Series C
Description: Torrance-based K2 Space develops high-power satellite platforms for orbital missions, using vertically integrated hardware and manufacturing processes. Founded by Karan Kunjur and Neel Kunjur in 2022, K2 Space has now raised a total of $425.5M in total equity funding and is backed by Lightspeed Venture Partners, Redpoint, Altimeter Capital, Alpine Space Ventures, and First Round Capital.
Investors in the round: Accel, Atlassian Ventures, CapitalG, Creandum, Databricks Ventures, DST Global, EQT Growth, Evantic Capital, HubSpot Ventures, Khosla Ventures, Kinship Ventures, Menlo Ventures, NVentures, Salesforce Ventures, T.Capital
Industry: Aerospace, Machinery Manufacturing, Manufacturing, Space Travel
Founders: Karan Kunjur, Neel Kunjur
Founding year: 2022
Total equity funding raised: $425.5M

7. Boom Supersonic $300.0M
Round: Series B
Description: Centennial-based Boom Supersonic is a commercial airplane manufacturer that builds supersonic airliners designed for speed, safety, and sustainability. Founded by Blake Scholl, Joe Wilding, and Joshua Krall in 2014, Boom Supersonic has now raised a total of $647.5M in total equity funding and is backed by Bessemer Venture Partners, Caffeinated Capital, 8VC, Y Combinator, and Karman Ventures.
Investors in the round: Altimeter Capital, ARK Investment Management, Bessemer Venture Partners, Darsana Capital Partners, Robinhood Ventures, Y Combinator
Industry: Aerospace, Air Transportation, Manufacturing
Founders: Blake Scholl, Joe Wilding, Joshua Krall
Founding year: 2014
Total equity funding raised: $647.5M

Get NYC’s daily tech and startup news delivered to your inbox

Subscribe Now

7. Radiant $300.0M
Round: Series D
Description: El Segundo-based Radiant develops portable nuclear microreactors designed to generate electricity and heat in a compact, factory-built form. Founded by Bob Urberger and Doug Bernauer in 2019, Radiant has now raised a total of $518.8M in total equity funding and is backed by Andreessen Horowitz, Tribe Capital, Draper Associates, Alumni Ventures, and Union Square Ventures.
Investors in the round: Align Ventures, Andreessen Horowitz, ARK Venture Fund, Boost VC, Chevron Technology Ventures, DCVC, Draper Associates, Founders Fund, Friends & Family Capital, Giant Ventures, IQT, Sahin Boydas, StepStone Group, Union Square Ventures, Washington Harbour Partners
Industry: Clean Energy, Energy, Energy Efficiency, Renewable Energy
Founders: Bob Urberger, Doug Bernauer
Founding year: 2019
Total equity funding raised: $518.8M

7. Eon $300.0M
Round: Series D
Description: New York-based Eon is a cloud backup posture management platform that provides instant access to all backed-up cloud data. Founded by Gonen Stein, Ofir Ehrlich, and Ron Kimchi in 2024, Eon has now raised a total of $497.0M in total equity funding and is backed by Lightspeed Venture Partners, Sequoia Capital, Bond, Affinity Partners, and Greenoaks.
Investors in the round: Center15 Capital, NightDragon, Principia Growth, Trajectory Ventures
Industry: Cloud Data Services, Cloud Management, Data Management, SaaS
Founders: Gonen Stein, Ofir Ehrlich, Ron Kimchi
Founding year: 2024
Total equity funding raised: $497.0M

6. Lovable $330.0M
Round: Series B
Description: Dover-based Lovable provides an AI-driven platform enabling users to generate and deploy web applications and websites from natural language prompts. Founded by Anton Osika and Fabian Hedin in 2023, Lovable has now raised a total of $552.5M in total equity funding and is backed by Menlo Ventures, Accel, Khosla Ventures, Creandum, and Antler.
Investors in the round: Hildred Capital, HLM Venture Partners, Toba Capital, Transformation Capital
Industry: Artificial Intelligence (AI), Developer Platform, Developer Tools, Software
Founders: Anton Osika, Fabian Hedin
Founding year: 2023
Total equity funding raised: $552.5M

5. Castelion $350.0M
Round: Series B
Description: Torrance-based Castelion is a defense tech company that applies modern hardware development and manufacturing processes to national security challenges. Founded by Andrew Kreitz, Bryon Hargis, and Sean Pitt in 2022, Castelion has now raised a total of $439.6M in total equity funding and is backed by Andreessen Horowitz, General Catalyst, Lightspeed Venture Partners, Valor Equity Partners, and Cantos.
Investors in the round: Affinity Partners, Bond, Gil Capital, Greenoaks, Lightspeed Venture Partners, Omri Casspi, Sequoia Capital, Swish Ventures, Vine Ventures
Industry: Aerospace, Government, Manufacturing, Military, National Security
Founders: Andrew Kreitz, Bryon Hargis, Sean Pitt
Founding year: 2022
Total equity funding raised: $439.6M

5. Erebor $350.0M
Round: Venture
Description: Columbus-based Erebor is a nationally chartered bank designed for the new innovation economy. Founded by Owen Rapaport in 2025, Erebor has now raised a total of $350.0M in total equity funding and is backed by Lux Capital, 8VC, Founders Fund, and Haun Ventures.
Investors in the round: AllianceBernstein, Atacama Ventures, B Capital, Breakthrough Energy Ventures, CalSTRS, Capricorn Investment Group, Carbon Equity, Centaurus Capital, Climate First, Congruent Ventures, CPP Investments, DCVC, Devon Energy Corporation, Echelon, Galvanize, Google, Impact Science Ventures, JB Straubel, Kris Singh, Liberty Mutual Investments, Marunouchi Innovation Partners, Mercuria, Mitsubishi Heavy Industries, Mitsui & Co, Sabanci Climate Technologies
Industry: Banking, Blockchain, Finance, Financial Services, FinTech
Founders: Owen Rapaport
Founding year: 2025
Total equity funding raised: $350.0M

4. Fervo Energy $462.0M
Round: Series E
Description: Houston-based Fervo Energy develops and operates clean energy technology to generate carbon-free energy from geothermal systems. Founded by Jack Norbeck and Tim Latimer in 2017, Fervo Energy has now raised a total of $1.1B in total equity funding and is backed by B Capital, DCVC, Mercuria, Galvanize Climate Solutions, and Galvanize.
Investors in the round: Goldman Sachs
Industry: Energy, Energy Efficiency, Energy Management, Nuclear, Renewable Energy
Founders: Jack Norbeck, Tim Latimer
Founding year: 2017
Total equity funding raised: $1.1B

3. Unconventional AI $475.0M
Round: Seed
Description: San Francisco-based Unconventional AI rethinks computer foundations to optimize energy efficiency for AI. Founded by Naveen Rao, Michael Carbin, Sara Achour,MeeLan Lee in 2025, Unconventional AI has now raised a total of $475.0M in total equity funding and is backed by Andreessen Horowitz, Sequoia Capital, Lightspeed Venture Partners, Databricks, and Lux Capital.
Investors in the round: Alpine Space Ventures, Altimeter Capital, Hedosophia, Lightspeed Venture Partners, Redpoint, T. Rowe Price
Industry: Artificial Intelligence (AI), Business Intelligence, Software
Founders: Naveen Rao, Michael Carbin, Sara Achour,MeeLan Lee
Founding year: 2025
Total equity funding raised: $475.0M

2. Saviynt $700.0M
Round: Series B
Description: El Segundo-based Saviynt offers an AI-based identity security platform that secures and governs all types of identities across digital ecosystems. Founded by Amit Saha, Atul Vij, and Sachin Nayyar in 2010, Saviynt has now raised a total of $870.0M in total equity funding and is backed by HPS Investment Partners, PNC Bank, Ten Eleven Ventures, Kohlberg Kravis Roberts, and Carrick Capital Partners.
Investors in the round: 8VC, Founders Fund, Haun Ventures, Lux Capital
Industry: Artificial Intelligence (AI), Cloud Data Services, Cyber Security, Enterprise Software
Founders: Amit Saha, Atul Vij, Sachin Nayyar
Founding year: 2010
Total equity funding raised: $870.0M

1. Databricks $4.0B
Round: Venture
Description: San Francisco-based Databricks is a data and AI platform that unifies data engineering, analytics, and machine learning on a lakehouse architecture. Founded by Ali Ghodsi, Andy Konwinski, Arsalan Tavakoli-Shiraji, Ion Stoica, Matei Zaharia, Patrick Wendell, and Reynold Xin in 2013, Databricks has now raised a total of $20.6B in total equity funding and is backed by Andreessen Horowitz, Blue Owl, Gaingels, NVIDIA, and Temasek Holdings.
Investors in the round: Andreessen Horowitz, Databricks, DCVC, Era, Future Ventures, Jeff Bezos, Lightspeed Venture Partners, Lux Capital, Naveen Rao, Sequoia Capital
Industry: Analytics, Artificial Intelligence (AI), Data Storage, Information Technology, Machine Learning
Founders: Ali Ghodsi, Andy Konwinski, Arsalan Tavakoli-Shiraji, Ion Stoica, Matei Zaharia, Patrick Wendell, Reynold Xin
Founding year: 2013
Total equity funding raised: $20.6B