Global stocks tumble as hot US inflation batters AI high‑flyers

On October 14, the US Labor Department reported that September CPI rose 3.7% year‑on‑year, beating market expectations and jolting global risk sentiment. The upside surprise sent Treasury yields sharply higher and triggered the worst one‑day loss for the S&P 500 since July, with selling heavily concentrated in technology names tied to the artificial‑intelligence boom. Many cloud and data‑center operators have financed AI build‑outs through corporate bond issuance, so higher yields translate directly into more expensive funding. Oracle, Dell and several chip and optical‑networking stocks fell roughly 9–11%, dragging the information‑technology sector to the bottom of the performance tables.

The tech rout quickly spilled over into Asia on October 15. Markets in Japan and South Korea, both packed with semiconductor and electronics heavyweights, saw broad declines as investors reassessed lofty AI‑related valuations. Shares that had been prime beneficiaries of the “AI trade” suffered the sharpest pullbacks, signaling a shift in sentiment from growth at any price to concern over financing costs and profit sustainability. The hotter inflation print also revived talk that the Federal Reserve could still deliver additional rate hikes, putting pressure not only on equities but on corporate credit and other risk assets. In the near term, volatility is likely to stay elevated while investors gauge how persistent the inflation surprise is and how much damage higher borrowing costs may inflict on earnings.