By the close, June 8 -- The circuit breaker activated at 9:14 in the morning, halting trading for twenty minutes across the Korea Exchange. It was not a glitch. It was the market admitting it had no idea what to price.

its steepest single-session loss since the index's historic 12-percent collapse in early March, when Iranian missile strikes first severed global semiconductor supply chains. The damage on Monday, June 8, was driven by a collision of three distinct shocks arriving within 72 hours of one another, and the confluence exposed a structural vulnerability that South Korean financial authorities had hoped they had already priced in.

None of the three crises was, by itself, fatal to the market. Together, they overwhelmed it.

On F...