Race is on for second place after Apple's $1trillion valuation

Amazon , Microsoft and Alphabet are locked in a tight race to become the second publicly-listed U.S. company to reach a $1 trillion stock market value after Apple became the first to touch the 13-digit milestone. Wall Street`s optimism about last year`s 10th anniversary iPhone, coupled with record share buybacks, have propelled Apple`s stock 34 percent higher over the past 12 months, pushing the company`s stock market value above $1 trillion on Thursday.

The Cupertino, California company`s shares added another 0.3 percent on Friday, putting its market capitalization at $1.005 trillion. Apple`s 12-month gain is far better than the S&P 500`s 14 percent increase over the past year, but it pales beside Amazon`s astounding 85 percent surge, propelled by the online retailer`s and cloud computing heavyweight`s scorchingly fast revenue and profit growth.

Amazon is now the second-largest publicly-listed U.S. company, with a market capitalization of $889 billion, followed closely by Alphabet and Microsoft, at $856 billion and $830 billion respectively. Google-owner Alphabet`s stock has risen 32 percent over the past 12 months, and is up nearly 18 percent in 2018. Together with Facebook , the five largest U.S. companies account for 15 percent of the S&P 500.  Synovus Trust portfolio manager Dan Morgan said he owns shares of Amazon mostly because of its dominance of the cloud computing industry, a business that grew 42 percent in the June quarter and provided most of Amazon`s operating profits.

"Of the three companies, I`d say Amazon will get to $1 trillion next," Morgan said. Average analyst price targets put Apple`s stock market value at $1.05 trillion, Amazon at $1.02 trillion, Alphabet at $970 billion and Microsoft at $953 billion, according to Thomson Reuters data.

To be sure, past stock gains are not a reliable predictor of future performance, and the surge in Amazon shares in recent years has been exceptional by most standards. But Amazon`s market capitalization would overtake Apple`s later in 2018 if both companies shares were to continue their 12-month growth pace.