SentinelOne

Primary category: edr-xdr. Also ai-runtime-security and ai-spm (via the Prompt Security acquisition).

One-liner — The main publicly traded EDR/XDR challenger to crowdstrike and microsoft-defender, whose Singularity platform now extends into GenAI security after acquiring prompt-security.

What it does

SentinelOne’s Singularity is an autonomous, AI-driven endpoint/extended detection and response platform (edr-xdr), spanning endpoint, cloud, identity, and data/SIEM (via the Scalyr acquisition), with Purple AI as its agentic SOC analyst. In 2025 it moved into AI security by acquiring Prompt Security, adding GenAI runtime protection — shadow-AI discovery, prompt-injection defense, and data-leakage prevention across browsers, desktop apps, and APIs — which maps to ai-runtime-security and ai-spm.

Where it sits in the stack

Foundation layer for its core (edr-xdr, with SIEM/siem-soc and agentic SOC adjacency). With Prompt Security folded in, it reaches the model/prompt layer (ai-runtime-security, ai-spm, ai-access-governance), screening untrusted input (prompt injection) and controlling sensitive-data egress. Spans green (managed endpoints) into yellow (AI app usage) trust zones.

Deployment & architecture

SaaS control plane with a single autonomous endpoint agent; API-first. Prompt Security’s protection runs across browser, desktop, and API channels — relevant for governing workforce GenAI use without an inline network proxy. Integrates with SIEM/SOC, IdP, and cloud platforms.

Positioning & differentiators

• Positions as the autonomous/AI-native EDR alternative to crowdstrike; usually the #2 considered in EDR bake-offs alongside microsoft-defender.
• Its AI-security M&A mirrors CrowdStrike’s almost beat-for-beat: SentinelOne bought prompt-security (GenAI runtime) the way CrowdStrike bought pangea.
• For the AI-security overlap, nearest neighbors are prompt-security (now itself), prisma-airs, cisco-ai-defense, hiddenlayer, witnessai.

Ownership, funding & M&A

Public company, NYSE: S, IPO June 2021; HQ Mountain View, CA; founded 2013 (Tomer Weingarten et al.). The seed flagged “acq Prompt Security” — CONFIRMED: announced 2025-08-05, combination of cash and stock, reported ~$250M (Calcalist; not officially disclosed), expected to close in fiscal Q3 FY2026 (SentinelOne later announced completion). Same announcement also covered the Observo AI (data pipeline) acquisition. See prompt-security. Confidence: high on the deal; medium on price.

CTO / hedge-fund lens

Day-1 foundational as an EDR/XDR option — the leading independent alternative if you don’t want CrowdStrike or Defender. The GenAI-security additions (Prompt Security, Purple AI) are a Day-2 consolidation benefit attractive to existing SentinelOne shops wanting AI runtime guardrails from their EDR vendor. Not an SR 11-7/model-risk governance tool; it’s security infrastructure. Fits enterprise and mid-market.

Competitors / alternatives

crowdstrike, microsoft-defender, palo-alto-networks (Cortex), cisco. AI-security overlap: prisma-airs, cisco-ai-defense, hiddenlayer, witnessai, pangea.

Open questions / to verify

• Final Prompt Security purchase price (press-reported ~$250M) and confirmed close date.
• How Prompt Security’s standalone product is packaged within Singularity going forward.

Sources

• SentinelOne to Acquire Prompt Security to Advance GenAI Security — fetched 2026-06-28 — supports: Prompt Security acquisition (2025-08-05), GenAI runtime rationale, fiscal Q3 close; confidence: high
• SentinelOne buys Prompt for $250M (Calcalist) — fetched 2026-06-28 — supports: ~$250M deal value; confidence: med
• SentinelOne IR / corporate facts — fetched 2026-06-28 — supports: public (NYSE: S), founded 2013, HQ Mountain View; confidence: high

History

• [2026-06-28] Stub created from seed registry.
• [2026-06-28] Researched; confirmed SentinelOne is public (NYSE: S, IPO 2021, founded 2013, Mountain View) and is the ACQUIRER — fixed ownership from acquired to public. CONFIRMED Prompt Security acquisition (announced 2025-08-05, ~$250M, close fiscal Q3 FY2026); noted Observo AI acquisition. Filled founding/HQ/deployment; set hedge_fund_fit high.