1.2 million retail investors in South Korea received margin call warnings this week. For those who can’t grasp how big 1.2 million is, let me break it down: That’s 3.4% of the entire adult population in South Korea. In other words, if you’re walking down the streets of Seoul, 1 in every 30 adults you see is currently at risk of having their brokerage account wiped out due to liquidation. On July 13, the 'Black Monday,' the KOSPI index plunged 8.95% in a single day, triggering full-scale circuit breaker alerts. Foreign investors and institutions led the sell-off, dumping nearly 3.9 trillion KRW in a single day, directly detonating the leveraged positions of retail investors.