CISO Tribune

Vendor comparison · 2 companies

ReliaQuest vs Stellar Cyber

ReliaQuest sells GreyMatter, an agentic AI security operations platform that allows security teams to detect, contain, investigate and respond to threats, regardless of the data source. Stellar Cyber sells a SecOps platform that uses AI for threat detection and response through unified NG-SIEM, NDR, and Open XDR capabilities. CISO Tribune files both under AI SOC analysts. This page sets the two records side by side: what each sells, where it is based, who owns and funds it, the customers it names and its recent news, each fact numbered to its source.

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  • ReliaQuest
  • Stellar Cyber
ReliaQuest vs Stellar Cyber: Products, Customers and Funding Compared
ReliaQuestReliaQuest sells GreyMatter, an agentic AI security operations platform that allows security teams to detect, contain, investigate and respond to threats, regardless of the data source.reliaquest.comStellar CyberStellar Cyber sells a SecOps platform that uses AI for threat detection and response through unified NG-SIEM, NDR, and Open XDR capabilities.stellarcyber.ai
What it sells
  • GreyMatter[1][2][3][4][6][7][8][9][10][11]An agentic AI security operations platform for security teams to detect, contain, investigate and respond to threats.
  • GreyMatter Detect[6][9]Centralizes all created rule logic in a library from any author.
  • Universal Translator[2][3]A patented way to normalize data collected from any source or technology.
  • Stellar Cyber Open XDR PlatformA SecOps platform that unifies SIEM, network detection and response, identity threat detection and response, and behavior analytics with AI-driven detection, investigation and response.
Categories
Headquarters
Not stated on its pagesNot stated on its pages
Founded
Not stated on its pagesNot stated on its pages
Ownership and funding
Not stated on its pagesPrivately held[3][4]
Named customers
Not stated on its pagesNot stated on its pages
Recent news
  • August 14, 2026Florida State Athletics named ReliaQuest its official jersey patch partner for men's basketball starting with the 2026-27 season.[12]
  • October 5, 2026Stellar Cyber announced version 7.0 of its security operations platform, adding AI case triage, case metrics and expanded automated response.[16]
G2 and Gartner Peer Insights
  • G2: listed, seen November 10, 2026[13]
  • Gartner Peer Insights: Not stated on its pages
  • G2: Not stated on its pages
  • Gartner Peer Insights: Not stated on its pages
Who it fits
ReliaQuest describes enterprises that adopt tools to keep up with evolving demands. ReliaQuest addresses organizations that manage security across multiple business units. ReliaQuest describes multicloud and multi-SIEM environments as ones that GreyMatter covers. ReliaQuest addresses organizations that run both OT and IT environments, including threats targeting critical infrastructure. ReliaQuest sells GreyMatter for environments that connect sources like SIEM, EDR, network security, and cloud tools.Stellar Cyber describes its open SecOps platform as built for lean security teams and MSSPs. Stellar Cyber designs its enterprise platform for security teams of any size or skill level. Stellar Cyber Open XDR can be deployed on-premises, from the cloud, or co-managed by an MSSP.
Last verified
November 6, 2026November 9, 2026

Where they overlap

  • ReliaQuest and Stellar Cyber are both filed under AI SOC analysts.

Where they differ, field by field

  • ReliaQuest's primary category is AI SOC analysts; Stellar Cyber's is SIEM.
  • ReliaQuest is also filed under External attack surface management, Digital risk protection and SOAR and security automation. Stellar Cyber is also filed under MDR and managed SOC.
  • ReliaQuest lists GreyMatter, GreyMatter Detect and Universal Translator. Stellar Cyber lists Stellar Cyber Open XDR Platform.
  • Stellar Cyber is privately held.

What it sells: ReliaQuest

What GreyMatter does[1][2][3][4][6][7][8][9][10][11]
GreyMatter includes 6 agentic Teammates that use hundreds of agent skills and AI tools to work toward an objective, not just tasks. GreyMatter detects threats wherever data lives, whether in the cloud, on the endpoint, inside a SIEM, directly at the source, or in transit. GreyMatter unifies detection, response, and visibility across a multicloud and multi-SIEM environment.
What GreyMatter Detect does[6][9]
GreyMatter Detect centralizes all created rule logic in its library from any author. GreyMatter Detect allows customers to test and validate detections before and after deployment and monitors their performance continuously.

Questions about ReliaQuest and Stellar Cyber

What do ReliaQuest and Stellar Cyber sell?
ReliaQuest sells GreyMatter, GreyMatter Detect and Universal Translator. Stellar Cyber sells Stellar Cyber Open XDR Platform.
Are ReliaQuest and Stellar Cyber in the same category?
They share AI SOC analysts. ReliaQuest's primary category is AI SOC analysts and Stellar Cyber's is SIEM.
Who owns ReliaQuest and Stellar Cyber?
Stellar Cyber is privately held.
Who are ReliaQuest and Stellar Cyber sold to?
ReliaQuest describes enterprises that adopt tools to keep up with evolving demands. Stellar Cyber describes its open SecOps platform as built for lean security teams and MSSPs.
What have ReliaQuest and Stellar Cyber announced recently?
August 14, 2026: Florida State Athletics named ReliaQuest its official jersey patch partner for men's basketball starting with the 2026-27 season. October 5, 2026: Stellar Cyber announced version 7.0 of its security operations platform, adding AI case triage, case metrics and expanded automated response.

About ReliaQuest

ReliaQuest sells GreyMatter, an agentic AI security operations platform that allows security teams to detect, contain, investigate and respond to threats, regardless of the data source. ReliaQuest states that it exists to Make Security Possible, allowing enterprise security teams to detect, contain and respond to threats using GreyMatter. GreyMatter includes 6 agentic Teammates that use hundreds of agent skills and AI tools to work toward an objective, not just tasks. GreyMatter includes persona-based agentic AI Teammates built on 10+ years of proprietary incident response data. GreyMatter collects data from any source or technology and normalizes it with the patented Universal Translator.[1][2][4]

GreyMatter detects threats wherever customer data lives, whether in the cloud, on the endpoint, inside a SIEM, directly at the source, or in transit. GreyMatter unifies threat detection, investigation, hunting, and containment across a customer's environment without requiring data to be moved. GreyMatter Detect centralizes all created rule logic in its library from any author. GreyMatter Detect allows customers to test and validate detections before and after deployment and monitors their performance continuously. ReliaQuest describes detecting threats at the source or in transit and moving and storing only what matters. ReliaQuest designs GreyMatter to be vendor-neutral. Customers connect GreyMatter with sources like SIEM, EDR, network security, and cloud tools.[6][7]

GreyMatter investigates, documents, and responds to routine alerts autonomously. GreyMatter automates phishing triage and applies shared intel for proactive defense across the ReliaQuest customer base. GreyMatter connects the steps between detection, investigation, and response with workflows tailored to the customer's business. ReliaQuest names Slack and Microsoft Teams as integrated tools for communication between users and business units. GreyMatter translates, normalizes, and correlates data to give a team a unified view. GreyMatter unifies tools such as email, network, and endpoint into one command system. GreyMatter lets teams find and fix vulnerabilities, prioritize what is exploitable, and validate risks.[4][8]

GreyMatter unifies detection, response, and visibility across a multicloud and multi-SIEM environment. GreyMatter correlates events across clouds and SIEMs, triggering automated playbooks. GreyMatter detects threats at the source across IaaS, PaaS, SaaS, and SIEM. GreyMatter integrates OT-specific technologies like Armis, Dragos, and Nozomi to enrich detection rules. GreyMatter correlates data from IT and OT sources, including firewalls, PLC logs, and remote access systems. GreyMatter bridges the gap between OT and IT environments. GreyMatter delivers metrics in a unified agentic AI SecOps platform. GreyMatter lets teams compare detection, investigation, and response performance across all entities to identify trends. GreyMatter lets teams benchmark data source visibility and coverage against peer organizations.[9][10][11]

ReliaQuest is headquartered in Tampa, FL, with operations centers in Tampa, Las Vegas, Salt Lake City, Dublin, London and Pune, India. ReliaQuest states a valuation of over $3.4 billion, over 1,200 team members and over 1,000 customers. ReliaQuest states revenue growth to more than $400M in 2025. Brian Foster is responsible for overseeing all areas of ReliaQuest's product development and technical operations. ReliaQuest states four values: being accountable, helpful, adaptable, and focused.[2][5][9][10][11]

ReliaQuest on the record

Sources

ReliaQuest full record

  1. [1]Reliaquest launches first autonomous self learning ai agent for security operationsReliaQuest · reliaquest.com · published September 26, 2024 · Tier A
  2. [2]reliaquest.comReliaQuest · reliaquest.com · undated page, accessed November 6, 2026 · Tier A
  3. [3]About UsReliaQuest · undated page, accessed November 10, 2026 · Tier A
  4. [4]Eliminate Tier 1 and Tier 2 Alerts with Agentic AI in ReliaQuest GreyMatterReliaQuest · undated page, accessed November 10, 2026 · Tier A
  5. [5]Home | ReliaQuest GreyMatter: The Agentic AI Security Operations Platform for Agentic DefenseReliaQuest · undated page, accessed November 10, 2026 · Tier A
  6. [6]Detect Everything Everywhere with ReliaQuest GreyMatter - Powered by Agentic AIReliaQuest · undated page, accessed November 10, 2026 · Tier A
  7. [7]ReliaQuest GreyMatter Integrations: Your Environment + Agentic AI Powered Security OperationsReliaQuest · undated page, accessed November 10, 2026 · Tier A
  8. [8]Agentic AI Solutions for SecOps - ReliaQuestReliaQuest · undated page, accessed November 10, 2026 · Tier A
  9. [9]Unified Multi-Cloud and Multi-SIEM Management with Agentic AI in ReliaQuest GreyMatterReliaQuest · undated page, accessed November 10, 2026 · Tier A
  10. [10]Securing Operational Technology with ReliaQuest GreyMatter, the Agentic AI PlatformReliaQuest · undated page, accessed November 10, 2026 · Tier A
  11. [11]Measure and Enhance SecOps Metrics with ReliaQuest GreyMatter - Powered by Agentic AIReliaQuest · undated page, accessed November 10, 2026 · Tier A
  12. [12]Florida State Athletics Announces Historic Jersey Patch Partnership with ReliaQuestReliaQuest · published August 14, 2026 · Tier A
  13. [13]ReliaQuest GreyMatter Reviews & Product DetailsG2 · undated page, accessed November 10, 2026 · Tier C

Stellar Cyber full record

  1. [1]ProductStellar Cyber · stellarcyber.ai · published February 25, 2026 · Tier A
  2. [2]Stellar cyber announces agentic ai autonomous soc in 6 4 0 releaseStellar Cyber · stellarcyber.ai · published March 16, 2026 · Tier A
  3. [3]Stellar cyber named one of americas best startup employersStellar Cyber · stellarcyber.ai · published November 21, 2024 · Tier A
  4. [4]ISOC Platform with AI SIEM, NDR, Open XDR & Multi-Layer AIStellar Cyber · undated page, accessed October 29, 2026 · Tier A
  5. [5]Stellar Cyber Automation-driven SecOps PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  6. [6]Stellar Cyber vs Sumo Logic: Expert SIEM Solution ComparisonStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  7. [7]Stellar Cyber vs Splunk: In-Depth SIEM Solution ComparisonStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  8. [8]Integrated Security Operations Center (ISOC) PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  9. [9]SC vs Microsoft Sentinel: Comprehensive SIEM SolutionStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  10. [10]SC vs. CrowdStrike | Compare Leading Cybersecurity PlatformsStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  11. [11]EDR Software, Endpoint Detection & ResponseStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  12. [12]Stellar Cyber Autonomous SOC PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  13. [13]Stellar Cyber Multi-Layer AI™ | Advanced AI Platform for SecOpsStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  14. [14]Stellar Cyber AI SIEM | AI-Driven SIEM PlatformStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  15. [15]Stellar Cyber vs AlienVault: In-Depth SIEM Solution ComparisonStellar Cyber · undated page, accessed November 10, 2026 · Tier A
  16. [16]Stellar Cyber 7.0 Makes the Agentic SOC Measurable, Actionable and Operational at ScaleStellar Cyber · published October 5, 2026 · Tier A

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