Apple (NASDAQ:AAPL) is drifting sideways since its last run up, most likely waiting for the fiscal Q2 results due on Monday (April 27). Currently it is up over 14.6% year to date, compared to the S&P 500 which is at just 1.8%. If, however, you look at the change since its 2012 high on September 18 (roughly $100, split adjusted), then it is up only 26.6% in the two and one half years, while the S&P is up 44%.
This is one reason bulls argue that Apple is undervalued. Another is that the PE ratio (TTM) of Apple is at 17 which is low compared to the S&P average (20.5) and Google (NASDAQ:GOOG) (NASDAQ:GOOGL) which is over 25.