European- and Asian-listed microchip stocks slumped Wednesday after Bloomberg News reported that Apple AAPL, +0.66% won't boost supplies of the latest iPhone after lower-than-expected demand. STMicroelectronics STM, -5.31% slumped 5% in Paris, ASM International ASM, -4.00% fell 4% in Amsterdam, Infineon Technologies IFX, -1.65% dropped 3% in Frankfurt and Taiwan Semiconductor 2330, -2.23% closed 2% lower in Taipei.