Microsoft hit the trillion-dollar value mark on Thursday for the first time, becoming the third technology giant to reach the symbolic milestone.
Shares in Microsoft rallied some five per cent to US$130.59 (NZ$196) in early Wall Street trade after a robust earnings report a day earlier.
That gave Microsoft a market capitalisation of just over US$1 trillion (NZ$1.5 trillion), before dipping back slightly.
At its current levels, Microsoft is the world's most valuable company, ahead of Apple and Amazon, which last year topped $1 trillion before slipping back.
On Wednesday, Microsoft said profits in the quarter to March 31 rose 19 per cent to US$8.8 billion (NZ$16.5 billion) on revenues of US$30.8 billion (NZ$46 billion), an increase of 14 per cent from the same period a year earlier.
The results were driven by growth in cloud computing and business services, the new focus for Microsoft after a long run as a leader in consumer software.
"This quarter was an absolute 'blow out quarter' across the board with no blemishes and in our opinion speaks to an inflection point in deal flow as more enterprises pick (Microsoft) for the cloud," said Daniel Ives of Wedbush Securities.
"While the stock has been very strong and a trillion dollar market cap is now reached, we believe the cloud party is just getting started in Redmond."