Wipeouts Threaten Korea Retail Army Chasing Riskiest Investments

When Tony Kim likes a stock, he goes all in. Literally.

The 34-year-old manager at a Seoul-based textile company never holds more than one stock in his 140 million won ($98,500) portfolio.

“Koreans, myself included, love that dopamine hit — it’s in our DNA,” the father of two said.

For many retail investors, that might seem like bravado — or an unusual resilience to stress. But among South Korea’s ants, as the roughly 14 million mom-and-pop investors are known, it’s just one example of a voracious and growing appetite for returns and risk.

That desire has driven a near-record shift of funds ...