Harpoon Ventures Closes $155M Fund IV as Dual-Use Venture Capital Accelerates

Harpoon Ventures closed an oversubscribed $155M Fund IV, increasing assets under management to more than $450M and giving the San Diego firm additional capital to back early-stage founders building critical technologies. The announcement matters because the firm has spent years investing where commercial markets, national security, AI infrastructure, cybersecurity, defense, energy, advanced manufacturing, and biotechnology increasingly intersect.

What Happened

Harpoon Ventures announced the close of its oversubscribed $155M Fund IV, a vehicle dedicated to backing founders developing critical technologies for the United States and its allies. The firm primarily invests at the Seed and Series A stages, and Fund IV increases its total assets under management to more than $450M.

The firm did not publicly disclose the identities of Fund IV's limited partners, though it noted participation from both new and returning investors. That matters because a successful fund close represents more than fresh capital. It reflects continued confidence from institutions that have evaluated the firm's investment thesis, founder access, and portfolio support across multiple market cycles.

Founder and Managing General Partner Larsen Jensen brings an uncommon background to the role. Before launching Harpoon Ventures, Jensen served as a U.S. Navy SEAL, earned two Olympic swimming medals, and held investing roles connected with Goldman Sachs, Andreessen Horowitz, and Lightspeed Venture Partners.

Why This Matters

Technology investing has moved beyond the neatly defined categories that characterized much of the previous software cycle. Many of today's most strategically important companies operate at the intersection of AI infrastructure, cybersecurity, advanced manufacturing, energy, defense, and industrial resilience, where customers may include both enterprise organizations and government agencies.

Harpoon Ventures built its identity around that convergence well before dual-use technology became a mainstream venture category. The firm's "Freedom Stack" thesis treats compute sovereignty, AI, energy, advanced materials, cybersecurity, aerospace, defense, manufacturing, robotics, biotechnology, and biosecurity as interconnected layers rather than isolated investment themes.

That perspective is becoming increasingly practical. AI depends on compute, compute depends on energy, energy infrastructure depends on cybersecurity, and national defense increasingly depends on commercial innovation. As those relationships deepen, companies operating across multiple layers of the stack become both commercially attractive and strategically significant.

Market Context

Investment in defense technology and critical infrastructure continues to expand as governments and enterprises modernize systems that were never designed for today's geopolitical and technological environment. Supply-chain resilience has become a boardroom priority, while founders are increasingly building companies capable of serving both commercial and government customers.

That environment creates an advantage for specialist investors. Writing a check is rarely the difficult part. Helping founders navigate procurement, federal funding programs, strategic partnerships, regulatory complexity, and long enterprise sales cycles often creates far more value than capital alone.

Harpoon's portfolio reflects that long-term strategy, with investments including Astranis, Solugen, Genesis Therapeutics, Semgrep, Material Security, Robust Intelligence, Kodiak, Merlin Labs, and n8n. Together, they illustrate the firm's focus on infrastructure, cybersecurity, autonomy, biotechnology, and AI-enabled systems rather than a single software category.

Competitive Landscape

Harpoon Ventures now operates in a market where dual-use investing has become increasingly competitive. More generalist venture firms are expanding into defense technology, AI infrastructure, cybersecurity, energy resilience, and advanced manufacturing as those sectors attract growing interest from founders, institutional investors, and strategic buyers.

The firm's differentiation lies in its operating experience and sector focus. Harpoon emphasizes supporting founders navigating government procurement, commercial adoption, and technically demanding markets where sales cycles may be long but competitive advantages can become highly durable. That requires a different approach than investing in horizontal software businesses built primarily around rapid product adoption.

The strategy also raises the bar. Success depends not only on selecting strong founders but on accurately evaluating market timing, procurement dynamics, technical execution, regulatory environments, and evolving geopolitical priorities. Those complexities also make deep specialization increasingly valuable.

What This Signals

Oversubscribed venture funds are confidence signals rather than victory laps. Institutional investors typically commit additional capital when they believe a manager has demonstrated repeatable judgment, differentiated founder access, and an investment thesis capable of generating returns across multiple market environments.

Fund IV reinforces Harpoon Ventures' position within critical technology investing. Expanding assets under management beyond $450M gives the firm greater capacity to support founders earlier and more consistently in sectors where operational guidance and long-term conviction often matter as much as capital.

For founders, the broader lesson extends beyond defense technology. The strongest venture firms tend to develop clear expertise around specific markets, understand where they can create differentiated value, and maintain conviction long before broader market consensus arrives.

The Bigger Industry Shift

Commercial opportunity and strategic importance are becoming increasingly aligned. AI infrastructure, cybersecurity, energy systems, advanced manufacturing, robotics, space technology, biotechnology, and defense no longer operate as isolated markets. They increasingly function as interconnected layers supporting both economic competitiveness and national resilience.

Harpoon Ventures built its strategy around that convergence years before it became a dominant venture narrative. Fund IV demonstrates continued institutional confidence in that long-term thesis. While no venture portfolio guarantees success, the firm's latest fund underscores a broader shift toward specialized investors backing the foundational technologies shaping the next generation of global infrastructure.