Over the past thirty years, financial decisions increasingly have been made with the benefit of extensive quantitative analysis. Major causes are the increasing complexity of financial markets, the ascent of computing and big data, and new developments in statistics and finance theory. Banks, investment managers, and other financial firms now routinely hire Ph.Ds in quantitative fields to work as quants. Physicists are desirable for their broad skills in mathematical modeling, data analysis, and scientific programming. In this talk I will describe the different kinds of jobs physicists do on Wall Street, how to find jobs, and what the transition from academia to finance is like. I finished my Ph.D. working in theoretical cosmology in 2005 and started a post-doc at Columbia immediately afterwards. In 2007 I moved to a quantitative hedge fund where I have worked since.