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Startup · United States

Horizon3.ai

HQ San FranciscoFounded 2019501-1000 employees

Horizon3 uses real-world attacks to safely show what attackers can actually do in your environment—so you can fix and prove what matters.

Startup
Website
Total raised
~$428M
7 rounds
Last round
$250M
Series E+ · Aug 3, 2026
Systems
2

Funding7 rounds · ~$428M

Equity raised
~$428M
Latest
$250MSeries E+ · Aug 3, 2026
Last valuation
$2.00BPost-money · Series E+ · Aug 3, 2026
Cumulative raised$428M
Jan 24, 2020Aug 3, 2026
Valuation over time$2.00B · Aug 3, 2026
Valuation over timeReported valuation rose from $12.5M (Jan 24, 2020) to $2.00B (Aug 3, 2026) across 6 valued rounds. 5 post-money, 1 without a stated pre/post basis.
Valuations by round
AnnouncedStageValuationBasis
Jan 24, 2020Seed$12.5MPost-money
Feb 1, 2021Series A$50.5MPost-money
Nov 2, 2021Series B$181MPost-money
Aug 8, 2023Series C$317MPost-money
Jun 10, 2025Series D$650MBasis not stated
Aug 3, 2026Series E+$2.00BPost-money

Raised counts equity rounds; debt, secondary sales and grants are totaled separately. Amounts in other currencies are converted at the announcement month's average rate. A ~ marks an estimated or converted amount.

Systems2

NodeZero

An AI platform for security testing in production environments.

Maturity not rated

NodeZero WebApp Pentesting

A module of the NodeZero platform that performs continuous, autonomous penetration testing of web applications.

Maturity not rated

Newest unveiled first. Open a system for its milestone timeline, components and sources.

People7

All 7 people →

Hiring Observations10 observed listings

View all 127 listings →

A sample of observed listings, not a total vacancy count. Availability may have changed since collection. Categories are inferred from job titles.

Sources17

Show all 17 sources and supporting evidence

Profile4

  1. 1
    DatabaseHorizon3.ai - PitchBook company profile

    PitchBook · Supports Organization · employee range, Organization · founded year, Organization · linkedin url, Organization · x url

    “employee_range: 501-1000 (profile: 550)”
  2. 2
    DatabaseSixth-Domain public startups directory

    Sixth-Domain · Supports Organization · country, Organization · kind

    “{"country": "USA", "hq_iso2": "US", "id": "280c9b9c-8089-43ca-ad3b-7ef7e9c8cdcd"}”
  3. 3
    DatabaseHorizon3.ai - LinkedIn company profile

    LinkedIn · Supports Organization · employee range, Organization · founded year, Organization · hq city, Organization · linkedin url

    “employee_range: 501-1000 (profile: 501-1,000 employees)”
  4. 4
    DatabaseHorizon3.ai - Owler company profile

    Owler · Supports Organization · founded year, Organization · hq city, Organization · linkedin url, Organization · x url

    “founded_year: 2019”

Systems1

  1. 5
    CompanyHome | Horizon3.ai

    Horizon3.ai · Supports Organization · description, Organization · name, Organization · website, System

    “Horizon3 uses real-world attacks to safely show what attackers can actually do in your environment—so you can fix and prove what matters.”

Funding10

  1. 6
    NewsHorizon3 triples valuation with $250m raise for AI security

    FinTech Global · Aug 4, 2026 · Supports Funding round · post money valuation usd

    “the $650m it commanded at Series D”
  2. 7
    NewsHorizon3 hits $2 billion valuation with $250M Series E as AI threats escalate

    TechCrunch · Aug 3, 2026 · Supports Funding round · post money valuation usd

    “raised a $250 million Series E at a $2 billion valuation”
  3. 8
    NewsCybersecurity firm Horizon3 crosses $2 billion valuation in new funding round

    Reuters · Aug 3, 2026 · Supports Funding round · amount, Organization · ownership

    “it has raised $250 million in its latest funding round”
  4. 9
    CompanyHorizon3.ai Secures Investment from Prosperity7 Ventures to Protect AI Datacenters and Critical Infrastructure

    Business Wire · Jan 13, 2026 · Supports Funding round

    “today announced an investment from Prosperity7 Ventures”
  5. 10
    CompanyHorizon3.ai Raises $100M to Cement Leadership in Autonomous Security

    Business Wire · Jun 10, 2025 · Supports Funding round · amount

    “today announced a $100 million Series D funding round led by NEA”
  6. 11
    CompanyHorizon3.ai Raises $40M Series C to Confront Attackers with Proactive, Continuous Security Testing

    Business Wire · Aug 8, 2023 · Supports Funding round · amount

    “announced $40M in Series C funding led by Craft Ventures with participation from Signal Fire”
  7. 12
    CompanyHorizon3.ai Raises $30M Series B to Disrupt the Pentesting Market

    PR Newswire · Nov 2, 2021 · Supports Funding round · amount

    “Horizon3.ai Raises $30M Series B to Disrupt the Pentesting Market”
  8. 13
    DatabaseHorizon3.ai - Forge company profile

    Forge Global · Supports Funding round · amount, Funding round · post money valuation usd

    “01/24/2020 Series Seed $2.5M $0.24 $12.5M”
  9. 14
    NewsFenwick Represents Horizon3.ai in $30M Series B Financing

    Fenwick · Supports Funding round

    “The financing round was led by SignalFire”
  10. 15
    NewsHorizon3 AI, Inc. announced that it has received $250 million in funding from a group of investors

    MarketScreener (S&P Capital IQ) · Supports Funding round · post money valuation usd

    “The transaction is being raised at a post money valuation of more than $2,000,000,000.”

People1

  1. 16
    DatabaseHorizon3.ai - Crunchbase company profile

    Crunchbase · Supports Organization · hq city, Organization · linkedin url, Organization · x url, Role

    “hq_city: San Francisco”

Other1

  1. 17
    CompanyHorizon3.ai public job board

    Supports Job posting

    “Enterprise Account Executive, Italy”

Each fact on this page is attached to the sources that support it. Archived copies are linked when we keep one.