Air Street Capital is a London-based venture firm founded in 2019 by Nathan Benaich that invests exclusively in AI-first companies across Europe and the US. Run as a solo-GP firm, it backs frontier AI models, AI infrastructure, applied software, TechBio and science, and defence and autonomy, with portfolio highlights including Synthesia, Black Forest Labs, Poolside, Profluent, Wayve and ElevenLabs. Air Street is famous for its research franchise - the State of AI Report, Air Street Press essays, RAAIS, and spinout.fyi. In March 2026 it closed $232M Fund III - the largest solo-GP venture fund in Europe - to lead early rounds with checks from $500K to $15M plus select growth investments up to $25M. Its disclosed portfolio spans four eras from 2019 to today, with exits to Amazon, SoftBank, Meta and others.
Air Street invests exclusively in AI-first companies - businesses for which advances in AI are the primary driver of product capability, competitive advantage and long-term value. It focuses on AI-first software (frontier models, AI SaaS, agents, world models), developer tools and infrastructure, TechBio and science, and defence and security, in the US and Europe.
The firm invests from Pre-Seed through growth, leading early-stage rounds of $500K to $15M and selectively making growth investments of up to $25M. As a solo-GP firm, a single decision-maker enables high-conviction, fast decisions with significant capital behind the most ambitious teams.
Beyond capital, Air Street is known for hands-on engagement on product, technical strategy and market positioning from day one, and for backing founders it has often known for years through its network, events and prior investments.
Air Street publishes the State of AI Report - the most widely read independent annual analysis of AI progress - essays via Air Street Press, runs the RAAIS research summit and the Air Street AI Network, and drove policy reform through spinout.fyi, using research-driven conviction to find non-consensus opportunities early.
Fund III vintage (announced Mar 2026): frontier AI, AI infrastructure, AI-for-science, defence and applied AI across Europe and the US.
European defence (EU)
Air defence (FR)
AI infrastructure (FR)
Defence (EU)
AI for science (UK)
AI video generation platform (UK)
Multimodal AI; open visual-intelligence models incl. FLUX (DE)
Fund II era: frontier evals, world models, robotics, TechBio, enterprise automation and defence/autonomy.
Frontier model evaluation (USA)
AI wealth management (UK)
Long-horizon reasoning agents (UK)
AI video (USA)
AI for clinical trials (USA/UK)
Maritime autonomy (EU)
AI game studio (USA/UK)
AI agents (UK) - acquired by Poolside
AI lifestyle software (USA)
Enterprise automation (DE)
World models / interactive AI (US/UK)
AI-first navigation for autonomous defence systems (EU)
Physical AI / embodied robotics for warehouses (DE)
AI knowledge discovery for finance (USA)
Programmable biology & protein language models (USA)
Fund I era: many companies since acquired (e.g. Adept -> Amazon, Graphcore -> SoftBank) or listed (Exscientia, Recursion).
AI agents (USA) - acquired by Amazon
AI diagnostics (AT) - acquired by Exscientia
AI + DNA-encoded libraries for drug discovery (USA) - acquired
Software-engineering metrics (FR) - acquired by Linux Foundation
AI cell-biology forecasting (UK)
AI visual content creation (FR) - acquired by Stability AI/Jasper
Video intelligence (UK/USA)
AI-driven pharma (UK) - NASDAQ: EXAI, merged into Recursion
Structural biology (CA)
Cultivated cell-based meat (FR)
AI semiconductors (UK) - acquired by SoftBank
Liquid-biopsy diagnostics (FI/CH)
AI workplace safety (TR)
AI protein therapeutics (UK)
Cultivated fat (USA)
AI for defence (USA)
Enterprise AI for software engineering / frontier coding lab (USA)
AI-driven pharma (USA) - NASDAQ: RXRX
AI-driven drug discovery (CA) - acquired by Recursion; now Valence Labs
Computer-vision data platform (UK)
Personalised nutrition from gut-microbiome science (UK)
Angel and personal investments made by Nathan Benaich before founding Air Street in 2019 (Stripe, Wayve, ElevenLabs, Synthesia and more).
Remote engineering teams (USA)
Lab automation systems (UK)
Open-source vector database for AI (USA)
Enterprise AI grounded in context / RAG (USA)
AI cloud / clean compute for frontier AI (USA)
AI audio and voice generation (USA/UK)
AI discovery of natural-product medicines (USA)
AI music generation (UK) - acquired by ByteDance
GPU cloud for AI training and inference (USA)
Street-level imagery and mapping platform (SE) - acquired by Meta
Climate & Earth-observation satellite constellations (USA)
Frontier AI research lab (USA)
Real-world AR games (USA) - acquired by Scopely
AI-powered hedge fund / data science tournament (USA)
Autonomous indoor vertical farms (UK)
AI voice assistants (UK)
AI fraud prevention (UK) - acquired by Worldpay
Engineering tools (UK)
Core-banking platform (UK)
AI for insurance claims (UK)
Autonomous last-mile delivery robots (EE)
Online payments (USA)
Embodied AI for autonomous driving - AV2.0 (UK)
No rounds led by Air Street Capital are in the tracker yet. Deals will appear here as they are recorded.