Amazon, Apple and Microsoft are in a tight race for the title of world's most valuable public company. The three have tossed around the title over the past few trading days, each closing with a market cap over $860 billion. Microsoft surpassed Apple in market cap on Friday, only for Apple to overtake it again on Monday. Amazon briefly eclipsed both companies during intraday trading Monday. As of Monday's close, Apple took the lead with a market cap of $877 billion. Amazon followed at $866 billion, then Microsoft with $860 billion.

The horse race between these tech giants has intensified as the tech sector has seen an upswing from October declines and following the White House's announcement of a 90-day trade truce with China on Saturday. The stocks have been closely watched since August, when Apple became the first publicly traded company in the U.S. to reach $1 trillion in market cap. About a month later, Amazon reached the same milestone before markets closed, ending the day just below the $1 trillion mark.

Microsoft's lead on Friday marked a significant shift in the tech sector, as the company hasn't closed a year in the top seat since 2002 and has not been the most valuable tech stock since 2010. While Apple and Amazon had been the two front-runners by market cap size, recent setbacks at the companies have given Microsoft a leg up. The company has seen its value more than triple since Satya Nadella took over as CEO from Steve Ballmer in February 2014, as Nadella has accelerated the company's transition into cloud-based services and allowed other parts of the business to take priority over the Windows PC operating system.

Since Apple announced on its fourth-quarter 2018 earnings call that moving forward it would no longer disclose iPhone unit sales, investors have worried the company is getting ready for a significant drop-off in sales of its flagship product.

Amazon saw a similar sell-off after delivering weak guidance in its third-quarter 2018 earnings report. The company expected $2.1 billion to $3.6 billion in fourth-quarter operating income, well below Street estimates of $3.9 billion for the quarter that spans the holiday season.

Both companies have rebounded with the market and the pause in trade tensions with China. On Monday, Amazon closed up 4.9 percent and Apple was up 3.5 percent.

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