Ostra Security Extends Series A to $9.5 Million

by Kay Aloha Villamor in August 8th, 2025

Ostra Security, an Eden Prairie, MN-based managed security platform, has extended its Series A round to $9.5 million. 

Investors 

The round was co-led by General Catalyst and Rally Ventures, with participation from Jeff Cowan of CapitalFour. 

General Catalyst is a global investment and transformation firm that partners with the world’s most ambitious entrepreneurs to drive resilience and applied AI. It supports founders with a long-term vision who challenge the status quo, partnering with them from seed to growth stage and beyond. With offices in San Francisco, New York City, Boston, Berlin, Bangalore, and London, General Catalyst has supported the growth of over 800 businesses. 

Rally Ventures is a U.S.-based venture capital firm founded in 2012 that invests in early-stage business technology companies focusing on sectors such as AI, cybersecurity, fintech, and SaaS+. With offices in Menlo Park, CA, and Minneapolis, MN, Rally manages over $1 billion in assets. 

Ostra Security Use of Funds 

The funding will accelerate hiring, deepen technical capabilities, enhance the company’s tailored service model, and integrate Blackwell Security’s MDR platform into Ostra’s offerings. 

About Ostra Security 

Ostra Security is a managed security provider dedicated to delivering outcome-driven protection for businesses without adding internal operational burdens. Its high-touch service model combines advanced managed detection and response (MDR) and extended detection and response (XDR) capabilities to help organizations effectively navigate risk. Headquartered in Eden Prairie, MN, Ostra provides end-to-end protection, including 24/7 monitoring, threat detection, and human-led remediation via solutions Ostra Encompass and Ostra Extend. 

Funding Details 

Company: Ostra Cybersecurity, Inc. 

Raised: $9.5M 

Round: Series A Extension 

Funding Date: August 2025 

Lead Investors: General Catalyst, Rally Ventures 

Additional Investors: Jeff Cowan (CapitalFour) 

Company Website: https://www.ostrasecurity.com/  

Software Category: Managed Security / Cybersecurity 

Source: https://www.prweb.com/releases/ostra-security-announces-extension-of-series-a-financing-bolsters-cyber-defense-with-blackwell-acquisition-302523857.html 

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