韓国株式市場が18日間で20%急落、15週間ぶり安値

CNBC and AFP/Yahoo Finance both confirm a sharp, rapid Kospi decline (10.84% in a single session, temporarily halted) concentrated in semiconductor and AI stocks (SK Hynix, Samsung) on Jul 28, 2026, with the index described as 'off >30%' from recent highs. This strongly corroborates the qualitative core of the claim — a large multi-day tumble reaching a multi-week low driven by semiconductor/AI pressure. The specific '20% in 18 days to a 15-week low' figures are consistent with the confirmed drawdown context, though sources reference an even larger peak-to-trough drop (>30%). The claim's substance is well-supported by authoritative primary news; the exact numeric framing is plausible but not precisely verified.