Amazon emerges as most valuable U.S. firm amid market turmoil

This May 3, 2018, photo shows boxes on a conveyor belt during a tour of the Amazon fulfillment center in Aurora, Colo. (AP Photo/David Zalubowski)

SAN FRANCISCO -- Amazon has eclipsed Microsoft as the most valuable publicly traded company in the U.S. as a see-sawing stock market continues to reshuffle corporate America's pecking order.

The shift occurred Monday after Amazon's shares rose 3 per cent to close at $1,629.51 and lifted the e-commerce leader's market value to $797 billion. Meanwhile, Microsoft's stock edged up by less than 1 per cent to finish at $102.06, leaving the computer software maker's value at $784 billion.

It marks the first time Amazon has held the top spot and ends Microsoft's brief return to the pinnacle after it surpassed Apple in late November .

The repositioning has been triggered by mounting concerns that the Trump administration's trade war with China and rising interest rates will bog down the worldwide economy. If that were to happen, it's likely to slow the growth of companies in technology and other industries that generate a substantial chunk of their revenue outside the U.S.

That's one reason most technology stocks are well off their peaks. Amazon, for instance, remains 21 per cent below its high reached in September when the company's stock value stood above $1 trillion. Apple was worth even more back then, but its stock has plunged by 37 per cent since early October to erase about $400 billion of its market value.

Apple confirmed some of investors' worst fears last week when it warned that disappointing demand for iPhones, especially in China, caused its revenue for its most recent quarter to fall well below the projections of its management and industry analysts.