About Marathon
Marathon is a venture capital firm founded in 2025. It is primarily based out of New York City, United States. As of Nov 2026, Marathon is an active investor, having invested in 5 companies, with 1 new investment in the last 12 months. It primarily invests in Seed round in United States based startups. Its investments are spread across a wide range of sectors from Enterprise Applications to High Tech and Enterprise Infrastructure. Most recently it participated in the $***** Seed round of Clark Overall, Marathon portfolio has seen 1 unicorn, namely Mercury. A lot of funds co-invest with Marathon, with names like Sequoia Capital sharing a substantial percentage of its portfolio. Marathon has team of 3 people including 3 partners.Key Metrics
Team Members
Portfolio Sectors
Portfolio Locations
Rounds of Entry
Seed, Series A & 1 more
Portfolio Unicorns
Marathon's List of All Investments
Marathon has a portfolio of 5 companies, one of which is a Unicorn. Their most notable investments are in Niural and UI Agent.Their portfolio spans across and United States. They have invested in Enterprise Applications, High Tech, Enterprise Infrastructure and 1 other sectors, across stages such as Seed, Series A and 1 more. Here is the list of all investments by Marathon:1. Mercury
Provider of a comprehensive online platform offering a range of financial services. The company provides integrated banking services for businesses, offering a platform to manage financial operations.
Key facts about Mercury
- Founded Year: 2017
- Location: San Francisco (United States)
- Annual Revenue: $1M - $10M as on Dec 31, 2021
- Valuation: $*****
- Stage: Series D
- Total Funding till date: $546M
- Employee Count: 1,807 as on Sep 30, 2026
- Investors: Harmony Venture Partners, Sapphire Ventures and 83 Others
- Latest Funding Round: Series D, May 08, 2026, $*****
- Highlight: Editors' Pick
2. Niural
Provider of payroll compliance and workforce management software for businesses. This platform automates tax calculations, regulatory filings, and international payment processing for organizations. It integrates human resources information systems with payment infrastructure to manage employee onboarding, benefits administration, and contractor payments. The system supports various employment models including employer of record and professional employer organization services. Users access tools for managing multi-currency wallets and cross-border financial transfers through a centralized dashboard.
Key facts about Niural
- Founded Year: 2022
- Location: Austin (United States)
- Stage: Series A
- Total Funding till date: $52M
- Employee Count: 170 as on Oct 31, 2026
- Investors: NewView Capital, FOG Ventures and 4 Others
- Latest Funding Round: Series A, Jun 03, 2026, $*****
- Highlight: Editors' Pick
3. Straiker
Provider of security software for monitoring and protecting autonomous agents. This technology maps agentic workflows and server configurations to identify potential vulnerabilities. It performs adversarial testing to detect risks such as prompt injection, goal hijacking, and unauthorized tool manipulation. The software provides runtime protection to block data exfiltration, identity abuse, and memory poisoning during active operations. These tools support governance and compliance requirements for organizations deploying automated systems across various technical environments.
Key facts about Straiker
- Location: Sunnyvale (United States)
- Stage: Series A
- Total Funding till date: $85M
- Investors: Workday Ventures, Firebolt Ventures and 9 Others
- Latest Funding Round: Series A, Jun 29, 2026, $*****
- Highlight: Editors' Pick
4. Clark
Developer of artificial intelligence software for accounting and audit firms. This platform automates bookkeeping, account reconciliations, and audit workpaper preparation. It integrates with existing financial systems to process client records and documentation. The software assists with month-end close procedures, revenue reconciliation, and financial reporting tasks. It provides tools for managing audit evidence and reviewing workpapers within a connected workspace.
Key facts about Clark
- Founded Year: 2025
- Location: New York City (United States)
- Stage: Seed
- Total Funding till date: $16M
- Employee Count: 50 as on Oct 31, 2026
- Investors: Touring Capital, Rerail and 1 Other
- Latest Funding Round: Seed, Nov 02, 2026, $*****
5. UI Agent
Developer of an AI agent for accounting operations and automation. The agent integrates with existing accounting tools to automate data extraction and reconciliation. It assists accounting teams by handling detail-oriented tasks and providing real-time insights. The agent aims to streamline workflows and maintain audit trails within current systems.
Key facts about UI Agent
- Location: New York (United States)
- Stage: Seed
- Total Funding till date: $4.6M
- Investors: Rerail and Marathon
- Latest Funding Round: Seed, Sep 15, 2025, $*****
Marathon's Year-on-Year Investment Trends
In 2025, it made 4 investments, while as of Nov 2026, it has made 2 investments in this year. Its most recent first time investment was in Straiker and most recent follow-on round was in Clark.Marathon's Investments by Stage
Marathon has made 2 investments in Seed stage with an average round size of $4.8M, 2 investments in Series A stage with an average round size of $47.5M and 1 investment in Series C stage with an average round size of $200M.Stage of entry | No. of Investments |
|---|---|
Seed | 2 |
Series A | 2 |
Series C | 1 |
Note: We have considered here, only first round of investments
Marathon's Investments by Sector
Marathon has a diverse portfolio, with companies operating in the Enterprise Applications, Artificial Intelligence - Industry Applications, Enterprise Infrastructure, FinTech and High Tech. Notably, it has invested in 5 Enterprise (B2B) companies, 5 Software companies, 5 Tech companies and at least 4 companies focusing on Saas.Sector | No. of Investments |
|---|---|
Enterprise Applications | 5 |
Artificial Intelligence - Industry Applications | 1 |
Enterprise Infrastructure | 1 |
FinTech | 1 |
High Tech | 1 |
Others | 1 |
Note: We have considered here, only first round of investments
Marathon's Investments by Geography
Marathon has made most investments in United States (5).Marathon's recent investments
Marathon has made 2 investments in 2026 so far - Clark and Straiker.Here are the most recent investments by Marathon:
Filter this listDate | Company | Location | Round Details | Round Amount | Co-Investors |
|---|---|---|---|---|---|
Nov 02, 2026 | United States | Seed | 7072 | [+1] | |
Jun 29, 2026 | United States | Series A | 7033 | [+9] | |
Sep 15, 2025 | United States | Seed | 4583 | ||
Sep 2025 | United States | Seed | 9083 | - | |
Jun 16, 2025 | United States | Series A | 9418 | [+2] |
Unicorns in Marathon's Portfolio
Marathon has 1 unicorn in its portfolio - Mercury. The most recent unicorn in their portfolio is Mercury which became a unicorn in 2021, 3 years before Marathon first invested in it.Here is a list of unicorns in Marathon's portfolio:
Tracxn Score | Company | Short Description | Founded year | Sector | Location | Company Stage | First Investment/ Acquisition Details |
|---|---|---|---|---|---|---|---|
84 | Provider of a comprehensive online platform offering a range of financial services | 2017 | San Francisco | Series D | f{cukif |
Team profile of Marathon
Marathon has a team of 3 members including 3 Partners located in United States. Marathon's team sits on the board of 1 company.Here is a list of all team members in Marathon:
Name | Designation | Location | Board Memberships | Contact Details |
|---|---|---|---|---|
Partner | San Francisco | |||
Partner | New York | - | ||
Partner | San Francisco | - |
Co-investors of Marathon
Over the past year, 58 investors have co-invested in Marathon's portfolio companies. This includes funds and angels.
- Invested before Marathon: CRV, Andreessen Horowitz and 37 others have invested in rounds before Marathon. There is 1 company where CRV has invested before Marathon and 1 company where Andreessen Horowitz has invested before Marathon.
- Top Co-investors of Marathon: 14 investors entered a company along with Marathon. These include investors like Sequoia Capital (1 company).
- Invested after Marathon: A total of 5 investors have invested in Marathon's portfolio after their investments. Top Investors include TCV (1 company), FOG Ventures (1 company) and NewView Capital (1 company).
Recent News related to Marathon
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Straiker Completes $64 Million Series A FundingSina•Jun 29, 2026•Illuminate Financial, Workday Ventures, Blossom Capital, Marathon and 3 others
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uiAgent Raises $4.6M Seed Round to Accelerate AI Agent Automation for Accounting Firmsintelligence360•Oct 03, 2025•UI Agent, Marathon, Rerail
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Niural Secures $31M to Enhance AI Capabilities on PEO PlatformPYMNTS.com•Jun 27, 2025•Marathon, Niural
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Niural Secures $31M to Revolutionize Global CFO and People Operations with AIRad AI•Jun 27, 2025•Niural, Marathon
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Niural Secures $31M to Revolutionize Global CFO and People Operations with AIPR Newswire•Jun 27, 2025•Marathon, Niural, M13 Company, Inspired Capital and 1 other
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Mercury Lands $300 Million Series Csvdaily.com•Apr 02, 2025•Mercury, Sequoia Capital, Andreessen Horowitz, CRV and 3 others
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Mercury secures USD 300 million in Series C investment roundThe Paypers•Mar 27, 2025•Sequoia Capital, Mercury, Spark Capital, Marathon and 3 others
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Mercury Announces $300 Million Series C Round at $3.5 Billion ValuationFintech Finance•Mar 26, 2025•Mercury, Sequoia Capital, Spark Capital, Marathon and 4 others
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Boon raises $20.5M to build agentic AI tools for fleetsTechCrunch+•Dec 20, 2024•Boon, Marathon Venture Capital, Redpoint Ventures, Marathon
