Apple Briefly Tops Exxon Mobil As Most Valuable Company in the U.S.

Stocks have been erratic today to say the least, with many more than paring yesterday’s huge losses and other continuing their downward spiral after S&P downgraded the U.S. government’s credit rating. As Exxon Mobil (NYSE:XOM) shares continued their descent, falling 3.69% today, Apple (NASDAQ:AAPL) shares began to rally. And though Apple shares are down 7.85% over the last five days, Exxon shares have fallen nearly twice that, allowing Apple to overtake the oil and gas giant as the most valuable company in the United States.

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Apple’s (NASDAQ:AAPL) market value rose Tuesday to $341.5 billion, just slightly above Exxon’s $341.4 billion, despite the fact that Exxon’s annual revenue is four times that of Apple’s. While Apple was quick to to give up its throne as it began shedding some of its gains in the afternoon, the fact that it momentarily topped Exxon, the most valuable company in the U.S. for five years running, is still a feat of mammoth proportions, especially when one considers Apple was brought back from the brink of extinction only a decade ago. At one point, Apple’s value consisted of a few real estate holdings and some cash on hand, and then came the iPod.

Today, Apple also joined a small group of companies that have held the top spot on the S&P 500, including General Motors (NYSE:GM), IBM (NYSE:IBM), Microsoft Corp. (NASDAQ:MSFT), and AT&T (NYSE:T). Apple’s market capitalization has risen more than $20 billion since the beginning of July on speculation about the newest version of its iPhone, expected out in the fall. In that same period of time, Exxon’s market cap has fallen by nearly $60 billion as crude prices have declined.