South Korean retail investors, affectionately known as “ants” for their collective strength in numbers, poured $4.6 billion into US equities in July. That’s their largest monthly haul since January 2026, and nearly double their average monthly purchases of $2.7 billion throughout 2025.
The timing is not coincidental. Back home, the KOSPI index just posted its worst monthly decline since the 2008 global financial crisis, dropping roughly 40% from its June peak.
A domestic market in freefall
South Korea introduced single-stock leveraged ETFs on May 27, and retail investors dove in headfirst. Those products attracted roughly 14 trillion won in net buying from retail participants, the equivalent of $9.4 to $9.7 billion depending on exchange rates at the time. When the underlying stocks, particularly AI darlings like Samsung Electronics and SK Hynix, reversed hard, the leverage worked in the opposite direction.
The damage was staggering. Estimated retail losses from leveraged positions totaled somewhere between $38.7 billion and $39 billion. More than 1.2 million accounts were hit with margin calls, affecting over 3.4% of South Korea’s adult population.
Foreign institutional investors weren’t sticking around to watch, either. In the month preceding the retail exodus, foreign investors dumped a record $30.72 billion worth of Korean stocks and bonds.
The “seohak ant” migration
When Korean retail investors buy overseas stocks, they earn a separate nickname: “seohak ants,” meaning ants who study abroad.
By June 2026, Korean retail holdings in US equities had reached nearly $200 billion, making South Korean individual investors one of the largest foreign ownership blocs in American stocks. July’s $4.6 billion surge only added to that already massive position.
The pivot toward US stocks marked the first time since February 2026 that net inflows into American equities outpaced new domestic investment from Korean retail.
Currency pressure and macro consequences
Data from Korea Securities Depository flagged the growing volatility of retail-driven capital flows as a systemic concern. Every dollar a Korean ant puts into Tesla or Nvidia is a dollar that gets converted from won, adding selling pressure on the local currency. Multiply that by $4.6 billion in a single month, layer on the $30-plus billion in foreign institutional selling, and you have a recipe for meaningful won weakness.
A weakening won creates a feedback loop. As the currency drops, Korean investors holding US stocks see their returns amplified in local currency terms, which encourages even more outflows.