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.<br />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.<br />Microsoft in turn eclipsed International Business Machines Corp two decades ago.<br />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.<br />Google's then-CEO Eric Schmidt left Apple's board the following year.<br />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.
