Micron Technology shares plunge 13% as global chip selloff deepens amid AI valuation concerns

Global semiconductor stocks sold off sharply with Micron Technology plunging 13% amid growing AI valuation concerns. South Korea's Kospi index fell 10% triggering a circuit breaker, while SK Hynix and Samsung Electronics each dropped around 12% on reports that SK Hynix is slowing AI memory chip expansion and shifting focus to lower-cost commodity DRAM. Rising expectations of a US Federal Reserve rate hike and investor doubts over whether hyperscaler capex can generate adequate returns further pressured the sector.