Alphabet Inc surpassed Apple Inc as the most valuable company in the United States in after-hours trading on Monday, knocking the iPhone maker from the top spot that it has held for the better part of four years.
The change may signal the passing of the technology baton to Alphabet - formerly known as Google - from Apple, which surged past Microsoft Corp in market value in 2010.
Microsoft in turn eclipsed International Business Machines Corp two decades ago.
It is not without piquancy for Apple and Alphabet, which worked hand-in-hand to develop mobile computing, but fell out bitterly after Google launched its own Android mobile operating system in 2008.
Google's then-CEO Eric Schmidt left Apple's board the following year.
The two companies' operating systems and apps are in direct competition with each other and Apple is still in litigation with Samsung Electronics, the biggest Android smartphone maker.