What happened

Shares of Amazon.com (AMZN 2.91%) climbed 5.8% on Monday to a new all-time high of $3,057. At that price, the e-commerce and cloud computing titan's market capitalization now exceeds a staggering $1.5 trillion.

So what

Positive economic news out of China likely contributed to the gains in Amazon's share price. Many of Amazon's third-party merchants source their goods from Chinese manufacturers. Shipping delays have weighed on these merchants' -- and, by extension, Amazon's -- sales and profits in recent weeks, and a return to more normal shipping times will be a welcome relief for businesses and customers alike.

A person is pointing to an upwardly sloping digital chart.

Amazon stock climbed above $3,000 for the first time on Monday. Image source: Getty Images.

From a longer-term perspective, what's driven Amazon's stock to such astounding heights is its dominance of not one, but two massive and rapidly growing markets: e-commerce and cloud computing. Amazon controls the lion's share of the online retail market in the U.S. and many other countries, and Amazon Web Services is the clear leader in the global cloud infrastructure market. Together, these enormous industries are projected to generate roughly $7 trillion in annual revenue by 2023. 

Now what 

Amazon's stock is an excellent example of one of the most important lessons an investor can learn: Winners tend to keep on winning. Since its initial public offering (IPO) in 1997, there's never been a bad time for long-term investors to buy shares of Amazon. Even today, this incredible stock remains an outstanding investment.