Amazon reached a $1 trillion market capitalization in 2018, becoming the second company to achieve that milestone.
Amazon crossed the threshold on September 4, 2018, about one month after Apple became the first company to reach $1 trillion. The online retailer's share price had risen dramatically as investors valued its expanding e-commerce operations, cloud division, advertising business, and subscription services.
Amazon was founded by Jeff Bezos in 1994 as an online bookseller. Its later development into a broad marketplace and technology company changed how investors assessed retail businesses. Amazon Web Services became a particularly important source of revenue and operating profit.
The $1 trillion figure describes equity market capitalization, not sales. Amazon's revenue, assets, and enterprise value are different measures. Its ranking can also change because market prices fluctuate throughout every trading session.