Title: Partner, Y Combinator; co-founder and board member, reddit; founder, Das Kapital Capital
Born: April 24, 1983
Education: BA in history and business, University of Virginia
Early Marker: Founded social news website Reddit with college roommate, Steve Huffman; sold to Condé Nast in 2006.
Big Idea: Early-stage start-up investing and open-Internet activism.
Wave of the Future: Social media