5. Key performance measures Measuring Stock Performance An informed and prudent investor uses a variety of measures such as financial ratios, book value, earnings per share, return on equity etc. to evaluate the worthiness and prospects of stocks he/she would invest in. It is important for you as an investor to understand how these values are calculated and what they mean.

Robert black, regional manager for ford in texas and oklahoma, faced a dilemma. the ford f-150 pickup truck was the best-selling pickup ever, yet ford's headquarters in detroit had decided to introduce a completely redesigned f-150. how could mr. black sell both trucks at the same time? he still had "old" f-150s in stock. in his advertising, mr. black referred to the new f-150s as follows: "not a better f-150. just the only truck good enough to be the next f-150." this statement represents ford's of the new f-150.