Fundraising Fox

24 Haymarket

Private equity

London · Seed–Series A · 7 people tracked

Fox Verdict
Sign up to see your fit

Investment thesis

24Haymarket follows a strict investment thesis focused on sectors in nascent stages of high growth where the firm can apply proprietary insights from its engaged investor network. The firm emphasizes initial commercial traction, active involvement with board representation, involved post-investment engagement, and syndication with aligned co-investors who commit their own capital. The team brings decades of collective entrepreneurial, investment, and operational experience to drive portfolio company optimization.

Invests inSector AgnosticLondon

Source: firm website, verified Jul 21, 2026.

Stage
Seed–Series A
HQ
London, GB
Leads rounds
Leads
Instruments
Equity
Tracked investments
51

Team · 7 people

from the firm's website
Lindsay Stuart· Co-founder

Lindsay is a co-founder and former Managing Partner of JPMorgan Partners Europe. His career also includes roles at Cinven, Prudential Venture Managers, and Candover.

Marek Gumienny· Founder Member

Marek is a founder member with substantial private equity experience across multiple sectors and geographies. He sits on boards of several portfolio and related companies including Brain in Hand, Hybrid Access, Equilume, Monterosa, and Cydar Medical.

Paul Tselentis· Co-founder and CEO

Paul is a co-founder and CEO with over a decade of private equity experience at The Carlyle Group and CCMP Capital, along with investment banking background at Lehman Brothers. He holds a BA in Economics from Harvard University.

Simon Leefe· Co-founder

Simon is a co-founder and former partner at Candover Partners Limited where he specialized in media and IT services investments. He studied English Literature at Exeter University.

Jamie Dunnett· Investment Director

Jamie joined 24Haymarket in 2016 as an Investment Director after five years in Transaction Services at Deloitte. He is a graduate of Durham University.

Alexandra Brown· Senior Associate

Alexandra joined 24Haymarket as a Senior Associate in 2022 with prior healthcare sector experience and four years at Accenture. She holds an MBA from London Business School.

Lucie Mazánková· Head of Operations and Compliance

Lucie joined 24Haymarket in June 2024 with over 13 years of financial services and family office experience. She previously managed investment operations at Weybourne, the private investment office of Sir James Dyson, and holds an MSc in Finance from Cass Business School.

What they invest in

from 4 of 51 portfolio companies

Marketing Tech ×2AdTech ×1Climate Tech ×1Cybersecurity ×1Data & Infrastructure ×1E-commerce ×1IoT ×1Media & Entertainment ×1

HQs:United Kingdom×1

Investments · 51 tracked

founders shown can be your intro path
Amicableamicable.ioin
Azadyneazadyne.comin
Blackbullionblackbullion.comin
Brain in Hand
Cambridgemedtechcambridgemedtech.com
Captinicaptini.com
Circulorcirculor.com
Client Loginforce.com
Cloudhousecloudhouse.com
Clustermarketclustermarket.comin
Cyberhivecyberhive.comin𝕏
CyberOwlcyberowl.ioin

CyberOwl develops Medulla, a cybersecurity platform that provides asset inventory, continuous security monitoring, and risk visibility for maritime and shipping fleets. The platform helps fleet operators understand cyber risks, ensure security controls are in place, and improve cyber hygiene across their operations.

CybersecurityIoTLondon, GB

Cydar Medical
Definigendefinigen.comin
Deliciouslyelladeliciouslyella.com
Equilume
Feebrisfeebris.comin
Flussoltdflussoltd.comin
Growthintelligencegrowthintelligence.com
Helloayrhelloayr.com
Huqhuq.io
Hybrid Access
Hypetexhypetex.comin𝕏
Insigniatechnologiesinsigniatechnologies.comin
Interfacepolymersinterfacepolymers.comin
Irisiris.netin
Keldatechnologykeldatechnology.com
Loveadminloveadmin.com
Lunamaelondonlunamaelondon.com
Medisievemedisieve.comin𝕏
Membrmembr.comin
Monterosamonterosa.coin𝕏
Mygworkmygwork.com
Optalitixoptalitix.comin
Ospreyflightsolutionsospreyflightsolutions.comin𝕏
Previsicoprevisico.com

Previsico provides flood forecasting and hydrological monitoring technology, enabling organizations to prepare for, mitigate, and prevent flood impacts through actionable warnings and real-time risk monitoring.

Climate TechData & Infrastructure

Privitarprivitar.com
proSapientprosapient.com
Revolobiorevolobio.comin𝕏
Rpdintlrpdintl.com
Smartiasmartia.tech
Spherefluidicsspherefluidics.com
Spirablespirable.comin𝕏

Spirable is a sport-focused media activation platform that helps advertisers connect with sports fans through targeted advertising and broadcast solutions. The platform also enables teams, leagues, brands, and sportsbooks to create immersive viewing experiences and build owned audiences through gamification and content tools.

AdTechMarketing TechMedia & EntertainmentSports Tech

Spoke Londonspoke-london.com
Subscribe to our newslettereepurl.comin𝕏

Mailchimp is an email and SMS marketing platform that helps businesses of all sizes automate customer communications and drive revenue through AI-powered analytics and campaign tools. It serves ecommerce retailers, small businesses, nonprofits, and content creators seeking to engage audiences and increase sales.

E-commerceMarketing TechSaaS

Tickxtickx.comin𝕏
Trackonomicstrackonomics.netin𝕏
Wattbikewattbike.com
Yasayasa.comin

Frequently asked questions

What stage does 24 Haymarket invest at?
24 Haymarket invests at the Seed, Series A stages.
What sectors does 24 Haymarket focus on?
24 Haymarket focuses on Sector Agnostic.
Where is 24 Haymarket located?
24 Haymarket is headquartered in London, GB.
Does 24 Haymarket lead rounds?
Yes, 24 Haymarket leads investment rounds.

Similar investors

500 Startups

500 Global's Sustainable Growth practice designs and implements sovereign-aligned strategies that unlock resilient, inclusive, and sustainable economic growth across the Global Majority—Asia, Africa, Latin America, and the Middle East. The practice bridges public priorities and private capital through ecosystem development, blended finance, and localized innovation programs addressing health, agriculture, gender, climate, and education.

8VC

8VC is a technology investment firm focused on building and investing in ambitious companies across life sciences, healthcare, manufacturing, enterprise, logistics, and defense sectors, with particular emphasis on operational intelligence and data-driven decision-making.

Accomplice

Accomplice is a venture capital firm that operates a federated model, serving as anchor LPs for solo GP funds and operating affiliated investment programs including Spearhead, an operator-angel network, and Accomplice Blockchain.

Andreessen Horowitz

a16z is a venture capital firm founded in 2009 by Marc Andreessen and Ben Horowitz that invests in seed through growth-stage technology companies across multiple sectors including AI, healthcare, consumer, crypto, enterprise, fintech, and gaming. The firm manages over $100 billion in assets and operates a distinctive platform model with a large team of operators supporting founders throughout their journey.

Aspect Ventures

Aspect Ventures partners with exceptional entrepreneurs to build transformative businesses, supporting portfolio companies across multiple technology sectors including IoT, cybersecurity, fintech, workplace communication, and wellness.

Featured in lists