This chapter explores the investing process. We discuss how to choose a broker and various aspects of broker–customer relations, including hypothecation and street name registration. The use of margin to purchase securities is covered, and the financial leverage effect of a margin purchase is emphasized. We describe short sales in some detail and stress the potentially unlimited losses that can arise from a short position. Finally, we cover some of the constraints faced by investors, and we briefly describe some basic investment strategy considerations, including market timing, asset allocation, and security selection.