Jim Simons’ brilliant mind made him a legend in finance, but his most important investments came through philanthropy, including all the work he and Marilyn led together through the Simons Foundation. As founder of Math for America, a major benefactor for Stony Brook University, a supporter of scientific innovation, and a funder of the fight against climate change, Jim was a force for progress on many of the most pressing challenges we face. The New York Climate Exchange on Governors Island that he was instrumental in founding, an effort Bloomberg Philanthropies was glad to support, will help ensure that his impact will continue to grow for many decades to come.