D Question 36 To simplify Markowitz's model, William F. Sharpe stipulated one fundamental underlying factor-the return of the stock market and instead calculated the variation of individual securities relative to this, rather than each securi relative to each other. In his formula, it was given the Greek letter And thus this became the lingua franca returns of the stock market as a whole, while later emerged as the term for the extra returns generated by investor. O kappa; iota Ojota; kappa O alpha; beta Obeta; alpha