IBM has surged past old rival Microsoft in market value for the first time since April 1996, marking the latest twist in the fluctuating fortunes of two of the world's most storied technology companies.
IBM ruled the computer industry for decades until it hired the tiny, unknown Microsoft to provide an operating system for its new range of personal computers in the early 1980s.
Bill Gates parlayed that breakthrough into industry dominance, proving his theory that software would be more valuable than hardware, so that by the end of 1999 Microsoft's market value was three times that of IBM's.
Throughout Microsoft's rise, IBM was pilloried as an old-fashioned, immobile Goliath that could not keep up with the computing revolution.
Since the Internet technology bubble burst in 2000, the tables have been reversed, and Microsoft's stock has been stagnant, as investors doubt its ability to move beyond its Windows operating system and Office suite of software, while younger rivals such as Google and Facebook steal the limelight.
In the meantime, "Big Blue" has refashioned itself as a specialist in business software, servers and consulting, jettisoning its PC business along the way.
An investor putting US$100,000 into both stocks 10 years ago would now have about US$143,000 in IBM stock and about US$69,000 in Microsoft stock.
Resurgent Apple moved past Microsoft in terms of market value last year, and is now by far the world's biggest tech company.
According to Reuters data, Apple's market value stood at US$308.3 billion on Monday, IBM at US$203.5 billion and Microsoft at US$201.1 billion.
(Reporting by Rodrigo Campos, David Gaffen and Bill Rigby; Editing by Phil Berlowitz).