Sergey Brin

Google co-founder Sergey Brin holds approximately $130 billion and returned to active Alphabet involvement to help lead the Gemini AI development team after years focused on personal projects. Brin co-created the PageRank algorithm that made Google search revolutionary, enabling the company to grow from a Stanford research project into the world's most profitable advertising business generating over $237 billion in annual revenue. He also funded Calico, Alphabet's longevity research subsidiary targeting diseases of aging, and has invested personally in lighter-than-air aviation (airships) as a personal project outside of Google.