Shares in Apple Inc. closed at an all-time high Wednesday at the lofty price of US$204.92 per share, a gain of $6.16 (+3.10%), on heavy volume of 42.55 million shares trading hands.

The stock traded as high as $208.7099 during the session, but gave back some gains shortly before the closing bell. Today's closing high beats the previous high of $202.96 hit on December 27, 2007.

Today's gains mean that AAPL is trading at a price-to-earnings ratio (P/E) of 35.8, with a market cap of $183.6 billion. In comparison, Dell Inc. currently has a P/E of 16.1 with a market cap of $29.6 billion. IBM has a P/E of 12.5 and a market cap of $158.4 billion. Microsoft's P/E is 16.4 with a market cap of $237.3 billion.

Generally speaking, high P/E ratios mean that investors are adding value for future earnings. Apple's P/E of 35.8 is considered high for technology companies.

Apple's gains come after a record quarter for revenue, earning, Mac unit sales, and iPhone unit sales, which were reported Monday. On Tuesday the company unveiled new iMacs, a new Mac mini, a new MacBook, and a new wireless, buttonless mouse called the Magic Mouse.

*In the interest of full disclosure, the author holds a small share in AAPL stock that was not an influence in the creation of this article.