KSE University, IT company Sigma Software, and defense startup Buntar Aerospace have announced the launch of a $5 million venture fund within the Defence Builder accelerator, which has effectively been operating in a non-public mode since March 2025. The new vehicle has become part of a broader ecosystem that combines an acceleration program, an investment fund, and an analytical platform created by the Kyiv School of Economics.
The project is led by Sigma Software Investment Director Daria Yaniieva, who was included in Forbes’ 30 Under 30 ranking in 2025. Defence Builder provides defense startups with comprehensive support, including deal сопровождение, due diligence, and assistance in building corporate governance.
The fund has been formed through $1.5 million in contributions from the founders, as well as investments from representatives of the IT industry and international partners. At the same time, the team is actively attracting investors from the UK, Europe, and the US. The acceleration program initially launched in April 2024 and focused on developing solutions for the Defense Forces, venture education, and giving startups access to funding.
Within the accelerator, participants received grants, the total amount of which exceeded $350,000 across three cohorts, while Defence Builder received up to 5% equity in the projects. However, in 2025 the team decided to shift to a classic venture investment model, increasing ticket sizes for more mature startups that needed direct investment rather than training.
During its first year of operation, the fund invested in four defense startups, including Sine Engineering, a developer of communication modules for drones; Falcons, a company creating electronic warfare and drone detection systems; Huless, a manufacturer of tethered drones; and MaXon Systems, a developer of autonomous interceptors. By the end of 2026, the fund plans to invest in another five to six companies, maintaining a high pace for a new market player.
The fund’s average investment size is up to $300,000. As a rule, it does not act as a lead investor, but it is often the first to enter a round, creating the foundation for attracting other participants. At the same time, the team is considering the possibility of changing its strategy within the next fund.
One of Defence Builder’s key advantages, according to market participants, is the speed of decision-making: investment deals can be closed within a few weeks, while at other funds this process can take months. In addition to financing, the fund provides startups with active support, including legal matters and intellectual property protection.
Each of the project’s founders performs a separate function: Sigma Software provides technological expertise, mentorship, and access to international markets; KSE provides the analytical and research base; and Buntar Aerospace contributes practical military experience and connections in the defense sector.
The acceleration program continues to develop: in March 2026, the third cohort started, and for the first time it includes foreign teams, whose share reached about 20%. They are viewed as part of the overall investment pipeline.
Earlier, 15 startups passed through the accelerator, including river drone developer Hard Cat and AI platform DroneMate AI, which later raised investment from international funds. In September 2025, management of the accelerator was transferred to Danish specialist Line Rindvig.
Against the backdrop of the growing defense technology market in Ukraine, the Defence Builder team is planning to launch a new fund that will allow it to make follow-on investments in portfolio companies. At the same time, market participants note that investment sizes are gradually increasing, and deals at the level of up to $100,000 are losing relevance, giving way to seed rounds starting from $1 million.
