This book is written for those physicists who want to work on Wall Street but have not bothered to read anything about Finance. This is a crash course that the author, a physicist himself, needed when he landed a financial data analyst job and became fascinated with the huge data sets at his disposal. More broadly, this book addresses the reader with some background in science or engineering (college-level math helps) who is willing to learn the basic concepts and quantitative methods used in modern finance. The book loosely consists of two parts: the ‘‘applied’’ part and the ‘‘academic’’ one. Two major fields, Econometrics and Mathematical Finance, constitute the applied.