Prelude Ventures manages capital exclusively for the climate-focused Simons family, creating a single-LP structure that demands strict venture returns from a 100% climate portfolio while applying a hard "no fossil fuels" rule that rejects any technology making oil, gas, or coal extraction cheaper or longer-lived. The firm combines deep technical operating experience with climate activism roots and has invested continuously through climate tech's "dark years" since 2009, positioning itself as a climate generalist comfortable with high capital intensity and long hardware timelines across the entire low-carbon economy.