# Horizon3.ai Raises $250 Million Series E at $2B+ Valuation

> Horizon3.ai has raised a $250 million Series E, co-led by NightDragon and New Enterprise Associates, at a post-money valuation above $2 billion. The August 3 round more than triples the roughly $650 million valuation the company carried at its Series D about a year ago, a sharp markup that reflects how hot autonomous security has become. The company's pitch is offensive security on autopilot. Its platform runs autonomous penetration tests, continuously probing an organization's systems the way an attacker would, then flagging the weaknesses that actually matter rather than dumping a long list of theoretical ones. The raise lands in a market suddenly crowded with AI-driven security startups, several of which have posted big rounds this year. Investors appear to be betting that as attackers themselves adopt AI, defenders will need tools that can keep pace automatically, and that continuous, machine-driven testing will move from a nice-to-have to a baseline expectation for enterprise security teams.

_Section: [AI Funding Tracker](https://www.wortins.com/funding) · Source: Crunchbase News · Published Wednesday, August 5, 2026_

## Wortins' read

Horizon3.ai has raised a $250 million Series E, co-led by NightDragon and New Enterprise Associates, at a post-money valuation above $2 billion. The August 3 round more than triples the roughly $650 million valuation the company carried at its Series D about a year ago, a sharp markup that reflects how hot autonomous security has become. The company's pitch is offensive security on autopilot. Its platform runs autonomous penetration tests, continuously probing an organization's systems the way an attacker would, then flagging the weaknesses that actually matter rather than dumping a long list of theoretical ones. The raise lands in a market suddenly crowded with AI-driven security startups, several of which have posted big rounds this year. Investors appear to be betting that as attackers themselves adopt AI, defenders will need tools that can keep pace automatically, and that continuous, machine-driven testing will move from a nice-to-have to a baseline expectation for enterprise security teams.

## Source

[Read the full story at Crunchbase News](https://www.unite.ai/horizon3-raises-250-million-series-e-at-over-2-billion-valuation-to-expand-autonomous-ai-penetration-testing/)

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