In May, most of the world’s largest technology companies — with the exception of Alphabet — expanded their market capitalisations by tens to hundreds of billions of dollars as investors responded to upbeat earnings signals and elevated demand for AI chips.
Apple led the monthly gains, adding $598 billion to reach a valuation of $4.58 trillion. Micron Technology followed with $512 billion in added market value, lifting its valuation to $1.09 trillion. Samsung Electronics and SK Hynix also posted substantial increases, adding $481 billion and $377 billion respectively, which brought their market caps to $1.10 trillion and $1.34 trillion.
Catalysts cited around those moves included product demand and corporate capital-return plans. In late April, Apple highlighted strong demand for its iPhone 17 and MacBook Neo and unveiled a fresh $100 billion share buyback. Samsung reported an eightfold increase in first-quarter operating profit in April. Micron attracted analyst upgrades after announcing that its 2026 high-bandwidth memory chips were already sold out and that next-generation HBM4 products were in production.
Other major technology names registered notable increases as well. Microsoft’s market value rose by $315 billion to $3.35 trillion, while Nvidia added $276 billion, taking its valuation to $5.11 trillion. Nvidia’s momentum included a May forecast for second-quarter revenue that exceeded expectations and the announcement of an $80 billion share repurchase programme.
Not all leading companies gained in May. Alphabet’s market value fell by $59.77 billion, ending the month at $4.59 trillion. Across the broader set of the 20 most valuable companies, firms outside pure technology also saw declines. Banking group JPMorgan Chase recorded the largest fall in market capitalisation, down $130.47 billion to $921 billion, and retailing giant Walmart’s market value dropped $37.3 billion to $802 billion.
Market context
The moves in May largely reflect investor responses to company-specific earnings signals, product demand commentary and sizable share buyback announcements, together with renewed emphasis on semiconductors used in AI applications.
What to watch next
Investors will likely continue to monitor forward guidance from large-cap technology companies, production updates from memory-chip manufacturers and buyback activity as signals that could influence market valuations in coming months.