Here’s S&P’s Howard Silverblatt via Brendan Conway at Barron’s:
Apple is trading at a new high of $695 per share (old high was $685.50), with a total market value of $651.5 billion. When I started at S&P in May of 1977 the entire market value of the S&P 500 was $623 billion (T was #1 with $38B, then IBM, XON, GM and GE – EK was #6 and S, which was Sears, was #7). It was not until August of 1978 that the index reached the $650 mark (when IBM was #1 with $43B, then T, XON, GM, GE, EK at #6, with S down to #9) – now, 34 years later, one company is $650 billion. So in October of 2046 will some issue be worth $13.9 trillion? FYI – the Aug,1978 to Sep,2012 full market value growth calculates to a 9.3% annualized rate (I have an app that calculates it – it called a hp12c, circa 1981, when T was back to being #1 in market value).