AI demand, earnings optimism lift tech giants’ market value in May

Tech giants (excluding Alphabet) added hundreds of billions of dollars in market value in May as AI chip demand and upbeat earnings outlooks fuelled a rally. Apple, Micron, Samsung and SK Hynix led gains — Apple added $598bn (valued $4.58tn) after strong iPhone 17 and MacBook demand and a $100bn buyback. Micron added $512bn as its HBM chips sold out and HBM4 entered production. Microsoft and Nvidia rose by $315bn and $276bn respectively (Nvidia now $5.11tn) after Nvidia guided Q2 revenue above expectations and announced an $80bn buyback. Alphabet bucked the trend, losing about $59.8bn. Outside tech, JPMorgan and Walmart posted the largest market-cap declines. Overall, the piece highlights AI-driven demand, product cycles and buybacks as key market drivers lifting tech sector valuations in May.