Semiconductor Surge Shifts Concentration Risk in US Growth Stocks

AllianceBernstein’s John H. Fogarty and Matthew Whitehurst examine how the Russell 1000 Growth rebalance has reshaped concentration risk for US growth investors.

• Magnificent Seven exposure fell from 52.8% to 43.1%, while semiconductors now represent roughly one-third of the index, up from 24%.
• Semiconductor stocks now contribute nearly half of index beta, increasing sensitivity to market swings.
• AB argues that shifting concentration reinforces the importance of broader diversification as AI-related leadership evolves.

Explore the full report to assess how changing index composition could affect portfolio risk and positioning.