How The Biggest U.S. Companies Have Changed Over A Decade - Apple (NASDAQ:AAPL), Amazon.com (NASDAQ:AMZN)

The five biggest U.S. companies based on market cap are all technology stocks. But going back ten years reveals a completely different story.

Today, the five biggest companies are as follows:

Apple Inc. (NASDAQ:AAPL).
Alphabet Inc (NASDAQ:GOOG) (NASDAQ:GOOGL).
Microsoft Corporation (NASDAQ:MSFT).
Amazon.com, Inc. (NASDAQ:AMZN).
Facebook Inc (NASDAQ:FB).

These are all high-tech companies not only investing billions of dollars in current high-tech initiatives such as cloud and voice assistant products but also investing billions more in next-generation technologies including self-driving cars, artificial and virtual intelligence. Even Amazon's ambitious longer-term goal is to operate a floating or flying warehouse at 45,000 feet in the air.

2006 Vs. 2016: The Tech Scene Emerges

10 Years Later: A Look Back At Apple's First iPhone Event Amazon May Be Unable To Achieve The Same Dominance In Cloud It Enjoys In Retail

Back in 2006, few if any people knew what the cloud was, and Amazon's Prime program had just launched a year prior with hardly any of the perks it comes with today.

For that reason, the biggest companies by market cap in 2006 were a handful of consumer good companies, energy companies and banks. After all, the iPhone hasn't even been released yet, oil was trading higher than versus today and the economic collapse hasn't been fully felt yet among Wall Street banks.

Here are the biggest U.S. companies by market cap in 2006: