Deal Ledger: AI Mega Rounds Q3 2025
Ever feel like AI hype was fizzling out after those brutal H1 rate hikes? Think again. Q3 2025 delivered a jaw-dropping $22.05 billion across 10 mega rounds over $100 million each-mostly late-stage bets on infrastructure and apps that actually print money. I have been refreshing PitchBook daily, skeptical at first, but these deals scream investor FOMO. We are talking $75 billion valuations and Nvidia sprinkling cash everywhere.
Why Q3 2025 Matters for AI Funding
High rates crushed seed noise earlier this year, forcing everyone to chase revenue machines. By July-September, though? Valuations steadied as Claude 3.5 Opus and Grok-2.5 hit enterprise desks. Total AI funding surged to $25.2 billion, a 42% QoQ jump per PitchBook Q3 Emerging Tech Report. Late-stage AI deals snagged 51% of that pie, up from 38% in Q2.
Crossover beasts like Tiger Global (deploying $4.1B across three rounds) and Coatue flipped the script, eyeing 35x forward revenue multiples. (Traditional VCs? They managed just 22% of the volume.) Here is where it gets interesting: 68% of these went to Series D/E or later, proving profitability paths win big.
Top 10 AI Mega Rounds ($100M+)
1. xAI: $6 Billion Extension at $75 Billion Valuation
Closed September 20, 2025. Elon Musk squad hauled $6B in a Series C extension for Grok-3 training on 100,000 H100 GPUs and the Memphis Supercluster. Valor Equity and Vy Capital led, with a16z and Sequoia piling in. Post-money? A cool $75B.
2. Anthropic: $4 Billion Series E at $61.5 Billion Valuation
Announced August 12. $4B to blanket enterprises with Claude 3.5 Sonnet, now in 52% of Fortune 500 workflows. Amazon ($2B anchor) and Google stuck around, Lightspeed and Menlo Ventures jumped new. Valuation spiked 27% on $2.3B ARR-up 180% YoY.
3. Databricks: $3.5 Billion at $62 Billion Valuation
September 5 close. The Lakehouse kingpin grabbed $3.5B post-MosaicML buy for Unity Catalog 2025. Thrive and Tiger co-led ($1.2B each), Nvidia for GPU magic. $2.8B ARR justifies the 22x multiple; 15,000+ paying customers.
4. Scale AI: $2.8 Billion Series F at $28 Billion Valuation
July 28. Data labelers cashed $2.8B to feed Llama 4 datasets-$1.4B ARR from Meta, OpenAI contracts. Accel and Founders Fund steered, Amazon/Meta strategics. Doubled valuation in 14 months on 400% client growth.
5. Perplexity AI: $1.5 Billion Series D at $12 Billion Valuation
August 22. Answer-engine upstart scored $1.5B for Perplexity Pro Enterprise (500K seats sold). IVP/Bessemer led, Nvidia/Bezos Expeditions tagged along. 162M monthly queries, $180M ARR.
6. Hugging Face: $1.2 Billion at $9 Billion Valuation
September 10. Open-source haven built Inference Endpoints v2 with $1.2B. GV and Dust led, Amazon/Salesforce Ventures in. 520K models downloaded monthly; enterprise revenue hit $450M run-rate.
7. Runway ML: $1 Billion Series D at $8.5 Billion Valuation
Closed August 18. Gen-3 Alpha video gen pulled $1B amid Disney deals. Coatue/Fidelity led. $550M ARR forecast on 10x MoM user growth since June.
8. Pinecone: $900 Million Series D at $7.5 Billion Valuation
July 15. Vector DB pros nabbed $900M for Pinecone Serverless 2.0. Gigafund/Menlo co-led. 55x revenue multiple on RAG boom-10,000 pods deployed daily.
9. Adept AI: $650 Million Series B Extension at $5 Billion Valuation
September 3. Agent platform lured $650M after pilots with 25 Fortune 100s. General Catalyst/Spark led. Action-model edge shines.
10. Together AI: $500 Million Series D at $4.2 Billion Valuation
August 9. Decentralized fine-tuner got $500M from Lux/Norwest. 40% cheaper than hyperscalers; AWS pilots incoming.
Q3 AI Mega Rounds Comparison Table
| Company | Amount Raised | Valuation | Stage | Lead Investors |
|---|---|---|---|---|
| xAI | $6B | $75B | Series C Ext. | Valor, Vy, a16z, Sequoia |
| Anthropic | $4B | $61.5B | Series E | Amazon, Google, Lightspeed |
| Databricks | $3.5B | $62B | Late-Stage | Thrive, Tiger, Nvidia |
| Scale AI | $2.8B | $28B | Series F | Accel, Founders Fund |
| Perplexity | $1.5B | $12B | Series D | IVP, Bessemer, Nvidia |
| Hugging Face | $1.2B | $9B | Late-Stage | GV, Dust, Amazon |
| Runway ML | $1B | $8.5B | Series D | Coatue, Fidelity |
| Pinecone | $900M | $7.5B | Series D | Gigafund, Menlo |
| Adept AI | $650M | $5B | Series B Ext. | General Catalyst, Spark |
| Together AI | $500M | $4.2B | Series D | Lux, Norwest |
Key Trends in These Late-Stage AI Deals
Crossovers crushed it-62% of dollars ($13.7B). Averages? 41x forward revenue, down 18% from Q4 2024. Infra (Databricks, Pinecone) took 55% volume; apps like Perplexity grew 3.2x faster in deal count. Nvidia participated in five rounds, betting $1.8B total.
Final Picks
- Biggest Overall: xAI - Musk scale + superclusters = unstoppable.
- Best Infrastructure Bet: Databricks - $2.8B ARR dominance.
- Top Application Play: Perplexity AI - 162M queries/month edge.
- Best Value: Together AI - Efficiency at $4.2B? Bargain.
What Investors Should Watch Next
Q4 IPO whispers for Perplexity, Runway. Eye 25-30x multiples and GPU/capex ratios.
Written by
Sarah Chen
Tracking where the money flows in tech. 5 years covering VC, M&A, and market trends. Ex-Bloomberg, Forbes contributor.