Factbox: Apple shares, a market darling, reach all-time high

(Reuters) - Apple Inc stock charged into unfamiliar territory on Wednesday, reaching an all-time high well above $500, before dipping in late trading.

The stock has risen more than 30 percent since the start of December, and its estimate-topping earnings late last month added fuel to its recent gains.

The shares touched a historic high of $526.29 on Wednesday, up more than 3 percent on the day, before closing down 2.3 percent at $497.67.

Here's a look at Apple's massive presence in the U.S. stock market.

* Apple's market capitalization is about $464 billion, more than the combined market cap of Google Inc ($197 billion) and Microsoft Corp ($252 billion)

* The earnings growth rate for the S&P 500 in last year's fourth quarter is 8.9 percent. Excluding Apple, the rate drops to 5.8 percent.

* The current estimated growth rate for the S&P 500 in the first quarter of 2012 is 2.25 percent, but without Apple it falls to 0.99 percent.

* Apple's median stock price target from Wall Street is $600, about 20 percent higher than its current price. The highest targets among the 57 analysts that cover the company are $700 from Hudson Square research and $670 from Piper Jaffray. Thomson Reuters StarMine's calculation of the stock's intrinsic value is now $637.10.

* So far in 2012, Apple's market cap has risen about $86 billion, from a price gain of 22.9 percent.

* Apple accounted for 9 percent of flows in the options market on Wednesday, with a total of 1.77 million contracts traded, according to Trade Alert. That was a record for contracts traded, exceeding the previous daily record of 1.3 million contracts set on February 9.

* The stock has had two down years in the last decade: 2002 and 2008. Its largest yearly percentage change since 1980 was 212 percent in 1998. The largest decline was 71 percent in 2000.

* In terms of price, the largest yearly change was $125.38 per share, in 2009. So far this year the stock is up $92.67.

* Apple is currently 16.5 percent of the Nasdaq 100. When its weighting tipped over 20 percent last year, Nasdaq OMX rebalanced the index and left Apple's participation at just above 12 percent.

(Reporting by Rodrigo Campos and Caroline Valetkevitch; Editing by Padraic Cassidy)