Margin calls unwind Korea's chip rally: Kospi down 40% from its June record

South Korea's Kospi peaked at 9,385.59 on June 19 after roughly doubling this year, then shed about 40% by July 30 — its worst month on record. Leveraged single-stock ETFs and margin debt turned a chip selloff into forced selling: Goldman Sachs counted 1.2 million margin-called accounts by mid-July, some 350,000 fully liquidated. Regulators tightened leverage rules; the index rebounded sharply Friday.