Image: Google Finance
Image: Google Finance

Apple Inc. (NASDAQ:AAPL) shares have been rising steadily since the company’s last earnings report, and finally investors pushed it up over $500 a share Today. The company’s stock finally passed its 200 day moving average — another major milestone — on Tuesday. Today’s milestone though is maybe an even more important one because the stock hasn’t hit $500 since January.

Apple AAPL

Apple extends its market cap lead

Thanks to these latest gains, Apple’s market capitalization has risen by an incredible $25 billion in only two days, putting it over $453 billion—far ahead of the second place company, which is Exxon Mobil Corporation (NYSE:XOM). The oil giant’s current market cap is closer to $392.2 billion.

Apple retook the lead for most valuable company by market cap earlier this month, but the two have been trading places for first and second since the beginning of the year. Only now is Apple Inc. (NASDAQ:AAPL) starting to pull away from Exxon Mobil in the market cap race.

What’s driving Apple shares?

Of course we can thank Carl Icahn’s tweet last night for this most recent boost, but Apple’s earnings and news about trade bans from the International Trade Commission have also given shares a boost over the last week or so. Investors are also looking forward to the unveiling of the next iPhone, which is expected on Sept. 10, and the launch of the device, which could come 10 days later.

What will Icahn do next?

Perhaps the biggest wildcard for Apple right now is Carl Icahn. While news of his investment in the company did drive the stock higher, we don’t know what he’ll do next. His nasty public spat with Dell Inc (NASDAQ:DELL)’s special committee showcases just how hard he will push to get what he wants. The question right now is, what does he want from Apple Inc. (NASDAQ:AAPL)?

Once his hand is fully revealed, there’s no telling what Apple Inc. (NASDAQ:AAPL) shares will do. If I were management at Apple, I’d be concerned about Icahn’s interest in the company.