Apple got edged out as the most valuable U.S. company on Friday after recent stock market activity pushed Exxon Mobil into the top ranking.

Apple stock has faced some challenges, and it was on Wednesday that the company released a quarterly earnings report that analysts found to indicate the tech company may see a slower rate of growth. As of 4 p.m. Friday ET, Apple was selling on the Nasdaq market for $439.88. Earlier in the day, it dropped 2.6 percent to $438.76 in afternoon trading. It also saw a significant 12 percent decline during Thursday trading.

According to The Los Angeles Times, as of mid-day Friday, Exxon saw a $417.59 billion market cap, while Apple saw a $412.36 billion market cap.

Furthermore, Exxon Mobil was the most valuable company between 2005 and 2011 until it was replaced by Apple. The two companies continued to exchange the top honor until Apple captured the top spot in early 2012 – that is, until Friday.

For comparison, as of Aug. 22, 2012, Apple was worth 53 percent more than Exxon Mobil, TechZone360 reported. It is also noteworthy that PetroChina may have higher market capitalization than either Exxon Mobil or Apple.

Needless to say, there are some concerns about Apple among investors. For example, Apple’s iPhone 5 was facing strong competition from phones using Google's Android software.

There are concerns too about the company’s recent record of innovation.

“It has been nearly three years since a new product has come from a company still seen as the embodiment of innovation,” the Huffington Post reported. “That last product, the iPad, came in 2010… Some analysts question whether Apple can keep growing by just releasing new versions of its old products. The long-rumored Apple TV, is still just that, a rumor.”

Generally, though, many investors are likely to keep their Apple shares, and this week’s performance is a far cry from 1997 when Michael Dell said if he led Apple, he'd "shut it down and give the money back to the shareholders," TechZone360 reported. On Oct. 6, 1997 Apple stock closed at $5.49 a share.