This is why I say that the stock price is a poor measure.
AAPL wrote:
In Dec. 31, 2007 AAPL had a PE of 43.53. AAPL is clearly regressing towards a mean in the range of 16 for the PE.
To give some more perspective of how relatively constant AAPL's PE has been since 2007, take a look at Amazon's PE.
http://ycharts.com/companies/AMZN/pe_ratioIt was in the 50s up until 2011, and now sky rocketed into the 300s. This is an example of a stock driven by speculation. Now go back and look at the AAPL PE. This is a mature stock with a relatively constant PE, driven by earnings.