Index Ventures
About Index Ventures
Lounge lists Index Ventures as headquartered in London, UK and San Francisco, US, and describes it as a Swiss venture capital firm. Lounge's records do not include its founding date, founders or current AI partners, so those are not covered here.
Lounge's deals desk records the firm in a steady run of AI rounds. Recent examples include Instinct's $250M Series B (2026-08) and Flapping Airplanes' $1B Series A (2026-10), both with the firm leading. Earlier rounds include Decagon's $250M Series D (2026-01), which the firm led, and Mistral AI's $2B Series C (2025-09), where the firm is listed without a lead flag.
Lounge's deal records show the firm at seed, Series A, Series B, Series C and Series D. Seed rounds in the records run from Augmeta's $3M to Flapping Airplanes' $180M. These are total round sizes, not the firm's own investment. Check sizes are not public, so none are listed.
- Fireworks AI: Series D round of $1.5B (2026-07), led by the firm
- Chai Discovery: Series C round of $400M (2026-07), led by the firm
- Instinct: Series B round of $250M (2026-08), led by the firm
- Decagon: Series D round of $250M (2026-01), led by the firm
- Mistral AI: Series C round of $2B (2025-09)
- Flapping Airplanes: Series A round of $1B (2026-10), led by the firm
- Oratomic: Series A round of $300M (2026-07)
- Granola: Series C round of $125M (2026-03), led by the firm
- Simile: Series A round of $100M (2026-02), led by the firm
Investing activity
Index Ventures appears in 26 AI deals tracked by the AI Lounge deals desk, rounds totalling $6.49B, and led 18 of them. The rounds are mostly Seed, Series A and Series C, with a median round size of $60M and the largest at $2B. The most recent are Flapping Airplanes (Series A, $1B, Oct 2026), Duvo (Series A, $32M, Oct 2026) and Albert (Albert Invent) (Series B, $55M, Oct 2026).
Index Ventures most often invests alongside Sequoia Capital, Nvidia, Coatue and Andreessen Horowitz, and the companies it backs on AI Lounge are mostly in AI, AI research models and AI agents / enterprise operations automation.
Deals
Frequently asked questions about Index Ventures
Which AI startups has Index Ventures led rounds for?
Lounge's deals desk lists the firm as lead on rounds including Fireworks AI (Series D, $1.5B, 2026-07), Chai Discovery (Series C, $400M, 2026-07) and Decagon (Series D, $250M, 2026-01).
Does Index Ventures invest at the seed stage?
Yes. Lounge lists seed rounds led by the firm, including Hone ($60M, 2026-10) and Enigma ($71M, 2026-07).
Where is Index Ventures headquartered?
Lounge lists the firm as headquartered in London, UK and San Francisco, US. Its website is indexventures.com.
What AI rounds has Index Ventures done most recently?
The newest rounds on Lounge's deals desk include Duvo's Series A ($32M, 2026-10), Albert Invent's Series B ($55M, 2026-10) and Flapping Airplanes' Series A ($1B, 2026-10).
How much does Index Ventures invest in each AI company?
Check sizes are not public. The round sizes on Lounge range from $3M to $2B, but these are totals for each round, not the firm's own investment.
What AI companies has Index Ventures invested in?
Index Ventures's AI investments include Flapping Airplanes, Duvo, Albert (Albert Invent), Hone, Augmeta, Ando, Ferry Health and Instinct. The 26 rounds on AI Lounge are listed on this page with amounts, dates and co-investors.
Where is Index Ventures based?
Index Ventures is based in London, UK / San Francisco, US.
What stage does Index Ventures invest at?
In the rounds tracked on AI Lounge, Index Ventures has invested at Seed, Series A, Series C and Series B, with a median round of $60M. Index Ventures led 18 of those rounds.
Who does Index Ventures co-invest with?
Index Ventures's most frequent co-investors on AI Lounge are Sequoia Capital (5 deals), Nvidia (3 deals), Coatue (3 deals), Andreessen Horowitz (3 deals) and Conviction (3 deals).
How can founders reach Index Ventures?
Founders on AI Lounge can see Index Ventures's contact details in AI Investor Contacts (paid plans), check for a warm introduction through members who worked with the firm under Warm Paths, and add Index Ventures to their Investor Pipeline to track the conversation.