@isosphere, In fact, this is just a summation of the change percentage of the stock. Suppose today they all start at 1, and change 1 percent, or 0.01 in price, then by Taylor's expansion, (1+0.01)(1+0.01)(1+0.01)(1+0.01)(1+0.01) is approximately 1+0.01*5 = 1.05. They totally changed 5%, roughly 0.05.
Hi Jesse. I'm not sure I really understand the value of multiplying together the share prices of each of these companies. Might you be able to explain your rationalization about why this is useful and what it potentially indicates?