Startup Trends: Q4 2025’s top funding rounds

The final quarter of 2025 delivered a wave of mega-rounds, with five Forge-listed private companies each securing $1 billion or more in fresh capital. These outsized raises not only show where late-stage capital is flowing — from AI to energy and event-driven markets — but also signal investor confidence that these companies have the potential to scale and deliver compelling, revenue-generating products. For investors, these billion-dollar hauls offer an early look at the emerging leaders that may shape the next decade of private-market returns.

Below is a snapshot of the quarter’s top five funding rounds and why they matter.

1. Reflection AI, $2 billion

Brooklyn, New York-based Reflection AI is a coding agent company that positions itself as an “open frontier” AI lab. Building superintelligent, open-source models, the organization provides tooling that can be embedded directly into software workflows. Reflection AI tops the list for the final quarter of this year for fundraising amount, with nearly $2 billion raised in an October Series B round.

Founded in 2024 by former Google DeepMind researchers Misha Laskin and Ioannis Antonoglou, Reflection AI closed its early-stage seed round of $130 million in March, led by Sequoia Capital and CRV. At the time, its founders stated that the company’s priority is to build a superintelligent autonomous coding platform with a future aspiration of developing other autonomous superintelligent systems using sophisticated LLM technology.¹

Reflection AI’s price per share as of its Q4 funding round is $27.65, putting its post-money valuation at $8 billion. Other notable investors include NVIDIA, Lightspeed Venture Partners and Alexander Wang.

2. Anysphere, $1.98 billion

Second on the list of highest funding rounds is San Francisco-based Anysphere. Founded in 2022, Anysphere offers a “vibe coding” experience that lets developers collaborate with AI to write and refactor software. Its lab has built an AI coding assistant dubbed “Cursor,” which helps engineers with debugging and understanding codebases.²

Anysphere closed a Series D funding round of $1.98 billion in November, which put its post-money valuation at $29.30 billion. According to the company, this latest funding round will “allow us to invest deeply in our research and build Cursor’s next magical moments.” The company told CNBC that it has now achieved $1 billion in annualized revenue, and its headcount sits at 300 employees.³

Anysphere’s Forge Price™ is $290.00 as of December 17, 2025. The tech startup’s notable investors include Thrive Capital, Andreessen Horowitz, Accel and Coatue.

3. Lambda, $1.5 billion

Tech startup Lambda ranks in the third spot on the list for Q4 capital raises. The software developer creates computing systems that drive scale and efficiency for AI and machine learning applications. Based in San Francisco, Lambda has a large suite of products such as its Lambda GPU Cloud, Vector Pro GPU Workstation, Scaler Server and Lambda Stack.

Founded in 2012, Lambda closed its Series E fundraise in November for $1.5 billion, putting its post-money valuation at $5.90 billion. CEO and co-founder Stephen Balaban said this new funding haul will “enable Lambda to develop gigawatt-scale AI factories that power services used by hundreds of millions of people every day.”⁴

Lambda’s Forge Price™ is $40.95 as of December 17, 2025, implying a valuation of $7.49 billion. Its notable investors include T. Rowe Price, NVIDIA, Gradiant Ventures and G Squared.

4. Base Power, $1 billion

Base Power is a modern energy platform that installs grid-connected home battery systems that can store excess power and provide backup during outages. Founded in 2023 and headquartered in Austin, Texas, the platform aims to modernize the U.S.’ electrical grid, improve resiliency, reduce costs and improve uptime for homeowners.

Base Power is fourth on the list of top fundraises in the quarter, raising its $1 billion Series C in October. This new capital puts the private company’s post-money valuation at $4 billion. According to Base Power, the company needs to deploy its hardware to add capacity for its products, something this funding will help it do. It has one production factory in Austin and is already planning a second.⁵

Base Power’s price per share as of its October fundraise is $11.76. Its list of investors include Addition, Trust Ventures, Valor Equity Partners and Thrive Capital.

5. Kalshi, $1 billion

New York City-based Kalshi is a regulated exchange dedicated to trading on a new asset class: event contracts. The company allows people to capitalize on their opinions by offering contracts on a wide range of topics, from weather to international affairs to media and more.

Founded in 2018, Kalshi ranks number five this quarter, achieving its $1 billion Series E fundraise in November and putting its post-money valuation at $11 billion. According to the company’s CEO, Tarek Mansour, “Kalshi is replacing debate, subjectivity and talk with markets, accuracy and truth.” The company announced that its trading volumes now surpass $1 billion per week, up 1000% from last year.⁶

Kalshi’s latest price per share is $320.76 as of this last fundraising round. The private company’s investors include Sequoia Capital, Andreessen Horowitz, Paradigm and Global Founders Capital.