The top ten US technology stocks now account for nearly 40% of the S&P 500's total market capitalisation, the highest concentration since the late 1990s tech bubble and well above the 25% recorded during the dotcom crash itself. UBS's Chief Investment Office has downgraded European IT to Neutral, citing 40% year-to-date gains and price-to-earnings valuations matching dotcom bubble highs, and urges investors to use periods of tech strength to reduce excessive concentration rather than add to it. The bank recommends broadening exposure beyond megacap leaders into lesser-known names, across sectors outside technology, and within the AI theme itself into infrastructure, industrials, automation and power supply chains. Taiwan Semiconductor Manufacturing's 30% May sales rise underscores continued capex cycle momentum, supporting medium-term constructiveness, but UBS warns that investors sitting on concentrated megacap tech positions face a clear tactical choice to rebalance during strength or accept the structural risks that historical patterns suggest accompany extreme concentration.
Apple Inc.
Amazon.com Inc
Alphabet Inc Class C
Microsoft Corporation
NVIDIA Corporation
Meta Platforms Inc.