It would appear that Apple has been overtaken by Exxon Mobil once again, with their respective market capitalizations turning face again for the second time this year. It was all the way back in August of 2011 that Apple first overtook Exxon to become the world's most valuable company, with Apple and Exxon's values fighting neck-and-neck right around $350 billion USD. Those numbers have since skyrocketed (so to speak).
Back in February of 2012, Apple reached above $500 billion in market value, they being only the sixth US-based corporation to have done so in history. Later that August, Apple became the most valuable public company in history with a market capitalization value at $622.6 - surpassing Microsoft's previous record of $618.9 billion in November of 1999.
This January (on the 5th to be exact), Apple reached down to a market cap of lower than $400 billion for the first time since it first reached over Exxon in 2011. The highest Apple has gone (thus far) was $705.07 billion USD, that peak being hit back on September 21st. That same day - you may remember - was the launch date for the iPhone 5. January also marked the first time that Exxon Mobil overtook Apple since 2011, having been re-taken by Apple one day later.
With Exxon taking Apple on the 22nd of February and retaining the lead straight through today, Apple has for the first time since it overtook the Oil beast back in 2011, become the second most valuable company on the planet for over a week. According to analysts speaking with Mercury News and MarketWatch, Apple is being projected to rebound to a price of $619.14 in the future - compared to the slightly larger than $420 the company is at today, such a rebound would likely catapult them above Exxon Mobil once more. We shall see!