VC's Take: Deep Tech Needs 'Obsessive Ambition'
Revent VC Otto Birnbaum says his firm looks for founders with "obsessive ambition to shape the world" when investing in deep tech like defense and aerospace. He also argues that timing is 95% of venture success, noting that many of today's climate and AI startups would have been impossible just five years ago.
Venture capital investment in aerospace and defense startups nearly doubled in 2025, surpassing $19 billion globally. This surge is fueled by a strategic shift from the Pentagon, which is now actively seeking to procure more technology from startups rather than traditional defense contractors to accelerate innovation. This trend is part of a broader venture capital pivot toward deep tech, which grew from 10% of global VC funding a decade ago to an estimated one-third of all venture funding in 2024. The current investment cycle is seen by some as a "once-in-a-generation reset of the technology stack" driven primarily by advancements in artificial intelligence. While Otto Birnbaum mentioned defense, his firm Revent primarily focuses on purpose-driven startups in climate, healthcare, and sustainability. Revent closed its second fund at €100 million in 2025 to back European startups that can generate over €100M in annual societal value alongside financial returns. The importance of timing is evident in the energy sector, where Birnbaum notes that the ability of AI to accurately predict renewable energy production and consumption has only recently made certain business models viable. Just five or ten years ago, the predictive analytics capabilities were insufficient to balance the grid at scale, making such ventures too risky. Investment in European robotics startups reflects this convergence of timing and technology, with funding more than doubling to €1.45 billion in 2025. This growth is driven by rising labor costs, manufacturing reshoring, and AI breakthroughs that are making commercial robotics and physical AI systems investable at scale for the first time. A record 10 new defense-tech unicorns were minted in 2025, with investors pouring over $48 billion into the sector. Major players attracting capital include Anduril, valued at $14 billion, alongside massive AI-focused rounds for companies like OpenAI ($110 billion) and Anthropic ($30 billion). Investors are increasingly prioritizing "dual-use" ventures—startups with technologies applicable to both commercial and government markets. Corporate venture arms from firms like Lockheed Martin and Boeing, alongside government-backed funds like
