Jan Hammer

Background

Jan Hammer is a Czech-born investor based in London, serving as a Partner at Index Ventures ¹². He joined Index in 2010, after working as an investor at General Atlantic and before that as an investment banker at Morgan Stanley ¹. Hammer holds an MBA with Distinction from INSEAD and is a graduate of Oxford University ¹.

With a focus on data and financial services, Hammer has built a track record of spotting early-stage companies that go on to reshape the workings of the digital economy ¹. He was an early-stage investor in Adyen (IPO 2018, market cap ~$56 billion), Robinhood (IPO 2021, market cap surged to $57 billion), and Wise (direct listing 2021) ¹². In 2025, Hammer was ranked number 50 on the Forbes Midas List, primarily on the strength of his Robinhood investment ².

Outside of investing, Hammer collaborates with the Tate gallery in London to expand its Central and Eastern European art collection ¹².

Stated Thesis

Hammer publicly describes his focus as backing “non-obvious, early-stage full-stack fintech and data infrastructure startups rebuilding core transaction and data flows” ¹. He emphasizes the systemic importance of financial services: “Financial services underpin every sector of the economy. That means entrepreneurs in this category can have an outsize impact compared to other areas” ¹.

His advice to founders centers on focus: “Start very narrow and solve an important problem in an industry that allows you to solve that problem a million times” ¹.

Hammer has articulated the importance of trust in fintech: “The underestimated variable is trust. Brand value creates trust. It’s both individuals to the brand, and it’s also to the whole category. It takes years, but once brands have built their brand, the whole asset class — the whole cohort — build a bundle of trust” ³.

He has also described fintech’s evolution: “Fintech is becoming horizontal rather than vertical. It’s becoming part of our daily life” ³. On full-stack models, he has stated: “There’s some merit to full-stack, but there’s also merit to [focusing] on product. The best companies both build their product and distribute” ³.

Hammer is a vocal advocate for European regulatory reform, arguing in Fortune in October 2025: “Europe doesn’t need another directive or committee. It needs its Delaware, and it needs it now” ⁴.

Inferred Thesis

Based on 16 verified investments in Hammer’s portfolio, the following patterns emerge. Note: Hammer has reportedly invested in 40+ companies ¹, so this represents a partial view.

Sector distribution (16 verified investments): - Fintech/financial services: 8 of 16 (50%) — Adyen, Robinhood, Wise, Capitolis, Apron, Moment, Alan, Codat - Data infrastructure/enterprise: 4 of 16 (25%) — Collibra, Cutover, SafetyCulture, Remote - AI: 1 of 16 (6%) — Mistral AI - Consumer/e-commerce: 2 of 16 (13%) — Rohlik, Taxfix - Crypto: 1 of 16 (6%) — Argent

Stage distribution: Hammer invests primarily at seed and Series A, with follow-on through Series B ⁵. His investment range spans $100K to $50M with a target of $15M ⁵. His highest-profile investments (Adyen, Robinhood, Wise) were all early-stage bets that he held through IPO.

Geographic distribution: Hammer invests across both Europe and the US, maintaining close collaboration with US-based partner Mark Xu ³. His portfolio skews European: Adyen (Netherlands), Wise (UK), Alan (France), Rohlik (Czech Republic), Collibra (Belgium), Taxfix (Germany), alongside US investments like Robinhood and Capitolis.

Co-investor patterns: Hammer works closely within the Index Ventures platform and frequently co-invests with other Index partners ⁵.

Notable pattern vs. stated thesis: While Hammer publicly emphasizes fintech, his portfolio also includes significant data/enterprise bets (Collibra, SafetyCulture, Cutover) and a notable AI investment (Mistral AI), suggesting a broader scope than his fintech branding implies.

Portfolio

This table represents approximately 16 of 40+ known investments. Years marked with ~ are approximate based on board appointment dates or founding year proxies.

In Their Own Words

“Financial services underpin every sector of the economy. That means entrepreneurs in this category can have an outsize impact compared to other areas.” — Jan Hammer, Index Ventures website ¹

“Start very narrow and solve an important problem in an industry that allows you to solve that problem a million times.” — Jan Hammer, Index Ventures website ¹

“The underestimated variable is trust. Brand value creates trust. It’s both individuals to the brand, and it’s also to the whole category.” — Jan Hammer, Sifted interview ³

“Fintech is becoming horizontal rather than vertical. It’s becoming part of our daily life.” — Jan Hammer, Sifted interview ³

“The banks have done ok, but look at the performance of technology. If you look at the financial sector, vs tech-enabled sector, the [latter] has outperformed by 2 to 3x.” — Jan Hammer, Sifted interview ³

“Europe doesn’t need another directive or committee. It needs its Delaware, and it needs it now.” — Jan Hammer, Fortune, October 2025 ⁴

What Founders Say

Baiju Bhatt and Vlad Tenev, co-founders of Robinhood, stated: “75 investors shut the doors in our face when raising our first round. Not Jan. He believed in us from the very start” ¹⁶.

Sources