D3 Venture Capital Firm | 3,006 followers on LinkedIn. D3 is an early-stage venture capital fund and accelerator for security startups. | D3 is an early-stage fund for defense tech startups. It offers equity investment, extensive mentorship by the world’s leading defense tech professionals, facilitated cooperation with the Armed Forces of Ukraine, as well as fundraising support. We focus on technology-driven startup that work with various defense capabilities across military hardware and software, cyber security, and AI.