Beware Of When The Debt Collector Come Calling
Published August 6, 2026
Borrowing money to buy stocks is as old as the stock market. Every era dresses it up in new clothes. In 1929, an American could buy $100 of stock with $10 down, and everyone from chauffeurs to senators did. This summer’s model made its debut in South Korea. The wrapper was new. The ending was not.
Once again, the monthly scoreboard belied the turmoil underneath. The S&P 500 slipped 0.1 percent to close at 7,490. The Dow rose 0.3 percent for its fourth straight winning month. The Nasdaq fell 3.2 percent. Under the hood, it was one of the wildest months in years. A $45 billion American hedge fund was forced into liquidation. The world’s hottest stock market, South Korea’s, fell almost 11 percent in a single day. American semiconductor stocks dropped 20 percent while their businesses reported unprecedented orders, profits and backlogs.
The KOSPI, Korea’s version of the S&P 500, was until July the best-performing major market, roughly doubling in a year. Two companies, Samsung Electronics and SK Hynix, make most of the world’s memory chips (the foundation of the artificial intelligence boom) and together represent roughly 60 percent of the KOSPI index. In late spring, Korean brokerages began marketing funds that borrowed money to double the daily moves of those two stocks, and margin debt hit all-time records. The average small investor was carrying about three borrowed dollars for every one of their own.
An investor who owns shares outright can ride out any storm. An investor who borrows to buy shares cannot, because when the price falls far enough, the lender wants its money back. That demand is a margin call, and investors who cannot pay have their shares sold for them […]

