For Jung Jae-hoon, a 37-year-old day trader in South Korea, the botched Trump-Kim summit was a success: The volatility that rattled the market helped him earn a nice profit.

Minutes before the market closed on Feb. 28, so-called peace stocks — a group of companies that stand to benefit from increased economic ties with North Korea — started to plunge on bets that U.S. President Donald Trump and Kim Jong Un would fail to reach an agreement at their Hanoi summit.

Jung seized the opportunity and bought shares in the group, adding some more the next trading day and selling them as they rebounded. In total, he invested about $300,000 and made as much as 10 percent from his bets.