In Seoul on Friday, a stock market defined by its intimate entanglement with the global artificial intelligence trade recorded its largest single-day gain in history, with the Kospi surging 14 percent on the back of strong U.S. tech earnings and a cascade of short-covering. The move capped a month of extraordinary volatility — panic giving way to euphoria and back again — that revealed how deeply leveraged and sentiment-driven the market has become. Whether Friday marks the beginning of a genuine recovery or merely the loudest note in an ongoing cycle of instability is a question that markets,