Amazon.com Inc. AMZN, -2.13% pushed past Apple Inc. AAPL, -1.78% as the biggest U.S. company by market capitalization in intraday trade, before its stock pared some gains. If Amazon could retake that position at the close, it would be the first time Amazon would hold that title, according to Dow Jones Market Data. With 488,968,628 shares outstanding as of Oct. 17, according to the most recent quarterly filing, Amazon's stock was up 4.9% to represent a market cap of $866.63 billion. At the same time, Apple's stock was up 2.1%, but with 4,745,398,000 shares outstanding as of Oct. 26, its market cap was $865.18 billion. Currently, Apple's market cap is $863.05 billion, while Amazon's is $862.36 billion. Microsoft Corp. MSFT, -1.26% was a not-so-distant third at $856.82 billion, based on the stock being up 0.7% and with 7,676,218,736 shares outstanding as of Oct. 19. Over the past three months, Amazon shares have shed 12%, Apple's stock has lost 20% and Microsoft's stock has slipped 0.6%, while the Dow Jones Industrial Average DJIA, -0.29% has eased 0.8%.