Apple surpasses Microsoft's market cap -- sort-of

According to MarketWatch, Apple's market capitalization as calculated by S&P rose today to  $241.5 billion, thus topping Microsoft's, which stood at $239.5 billion. The "market cap," as this key financial metric is often called, represents the total value of all outstanding shares of a company--in other words, the number of shares times their price. That makes market capitalization an indicator of how much the markets that a particular company is worth, rather than an objective measurement of a company's assets and liabilities. The S&P 500 index, in particular, is based on a company's "float-adjusted" market cap--that is the value of all shares that are available on the market for sale at any given point in time. While that's of particular interest to investors--who, after all, are looking to actively trade in a stock--this number doesn't include shares that are held by investors who are not interested in trading. And that makes a big difference: when shares of both companies are taken into consideration, Microsoft's full market cap still outstrips Apple's by $275 billion to $241 billion. Why the difference? Perhaps it's because investment circles consider Microsoft a stable company that makes sense as a long-term investment due to its more established nature; Apple, which is still growing aggressively, is looked upon as a slightly more speculative opportunity. This would explain why practically all the company's shares are floating on the market--that is, Apple's float-adjusted and full market caps are essentially the same. Therefore, this milestone appears to be more psychological than anything. It's a bit like trying to decide who the richer of two people is based on the amount of cash they have in their wallets. Still, it's a clear sign of the fact that the financial markets are responding well to Apple's strategy for growth and innovation, which have led the company to the record revenues and profits .