Deal Ledger: AI Mega Rounds Q3 2025

Q3 2025 delivered the busiest quarter for AI mega rounds since 2021. Crossover funds and strategics returned in force, anchoring USD 100M-plus checks across foundation models, infrastructure, and vertically focused AI plays. Use this ledger to calibrate valuations, identify strategic partnerships, and anticipate follow-on demand heading into 2026.

Snapshot

• Total mega-rounds: 32 disclosed financings at or above USD 100M, up from 19 in Q2.
• Capital deployed: USD 21.4B across all stages, with late-stage rounds capturing 74 percent.
• Median round size: USD 245M; the top quartile cleared USD 410M.
• Valuations: Median post-money valuation reached USD 5.8B for Series C and later rounds, up 16 percent quarter over quarter.
• Strategic participation: 41 percent of mega rounds included Big Tech, semiconductor, or telecom corporates trading compute or distribution access for equity.

Top Deals

Data sourced from Crunchbase, PitchBook, and public disclosures through September 30, 2025.

Sector Highlights

Foundation Models

• Compute-for-equity is the new norm. AtlasFoundry signed multi-year GPU supply deals with Oracle and Google Cloud as part of its raise, ensuring capacity for 2026 training runs.
• Diverse modalities. LuminaWorks and two stealth companies raised to expand video and audio comprehension, positioning themselves against OpenAI's next release cycle.
• Regulatory readiness. All major raises referenced EU AI Act compliance budgets, a theme we also cover in our EU AI Act countdown guide.

Infrastructure and Tooling

• Operational tooling premium. AuroraOps and VectorForge demonstrate investor appetite for software that tames model deployment and observability. Both cited 140 percent net revenue retention.
• Security spotlight. Vauban Secure AI raised to expand continuous policy enforcement, bundling assessments that help enterprises prove controls for regulators and insurers.
• Data layer bets. Several undisclosed rounds targeted vector storage, feature management, and governance pipelines that reduce total cost of ownership for AI stacks.

Applied AI

• Energy and industry momentum. Helios Grid AI and Kinetic Automata show how industrial digital twins and robotics capture mega checks when paired with decarbonization outcomes.
• Healthcare validation. Synthex Labs and ClarityMed both secured regulatory milestones (UK MHRA clearance, US FDA Breakthrough designation), reducing adoption friction.
• Fintech expansion. BridgeFin AI is scaling underwriting tools into LatAm, highlighting demand for AI that improves credit access amid macro volatility.

Investor Activity

• Crossover funds (Tiger, Coatue, Dragoneer) led or co-led 53 percent of disclosed deals, up from 34 percent a year ago.
• Sovereign wealth funds (GIC, Mubadala, Temasek, QIA) appeared in 12 mega rounds, often anchoring with conditional follow-on rights.
• Corporate venture arms from cloud, semiconductor, and telecom companies participated in 14 financings, exchanging compute credits, specialized hardware, or distribution partnerships for equity stakes.
• Debt stacks accompanied seven deals, bundling venture debt or structured equity to extend runway without diluting founders further.

Outlook

• Pipeline: Expect at least 10 AI companies to test public markets in 2026 if revenue trajectories hold. Several in this ledger hired CFOs with IPO experience in Q3.
• Valuation discipline: Investors are rewarding efficient growth. Companies below the Rule of 40 reported more challenging diligence and capped valuations.
• Secondary liquidity: Employee liquidity programs expanded, with board-approved secondary sales at a 10 to 15 percent discount to round pricing.
• Next catalysts: Watch for government incentives tied to AI infrastructure, which could subsidize capital expenditures and further buoy valuations into 2026.

Sources and References

• Crunchbase Emerging Tech Indicator Q3 2025
• PitchBook Emerging Tech Indicator Q3 2025
• Dealroom Global AI Funding Tracker