The Financial Post reports in its Wednesday edition that a rout in tech stocks dragged U.S. indexes down Tuesday after a sell-off in Korean chipmakers raised concerns about the sustainability of the artificial-intelligence-driven rally. The Post's Geoffrey Morgan writes that the S&P 500 opened 1.3 per cent lower, with Nvidia and Micron Technology among the biggest drags on the index. Tech is leading markets lower "as a heavy sell-off in Asian chipmakers, including a 10 per cent drop in the South Korean Kospi index, is dragging broader equity markets lower amid valuation and capex worries," says Seven Reports founder Tom Essaye. Micron tumbled over 11 per cent ahead of its quarterly results on Wednesday. The stock has been this year's top performer in the Philadelphia Semiconductor index, rallying more than 300 per cent since January before Tuesday's drop. The tech rally has stumbled this month as investors are concerned that share prices, especially of big tech companies investing heavily in AI, may have risen too much. Jonestrading's Michael O'Rourke says: "Hyperscalers are the new software stocks. The group can't get out of its own way as it leads the Magnificent Seven megacaps lower."