The Double Loss Didn't Happen Today. That's the Part Worth Watching.
Monday’s US close was not dramatic. The S&P 500 finished at 7,619.98, down 0.48% on the day. The Nasdaq 100 was worse but still ordinary, down 0.82% to 29,127.16. The VIX rose 7.95% to 17.1, which is the kind of move that registers as nerves rather than fear. On its own, a session like this is not worth writing about.
Trading US Markets from Seoul means I read those numbers in the morning, next to a currency screen that has already moved. The won’s reference rate closed at 1,346.4 to the dollar, up 0.61% from 1,338.2 on Friday. The US Dollar Index was up 0.34% to 99.488. So: US stocks down, dollar up, on the same day.
For someone holding US stocks from the won side, that combination is not a loss twice over. It is the opposite. The dollars sitting in the account became more expensive in won, and the currency moved more than the S&P 500 did — 0.61% against 0.48% — and covered most of the Nasdaq 100’s 0.82%. Converted back, the day was close to a wash: the account fell in dollars and barely fell in won.
The Hedge Nobody Chose
Every Korean investor who buys US stocks directly is running two positions, whether they wanted the second one or not: the equity, and a long dollar position underneath it. Nobody signs up for that second one on a form. It comes attached. And in every drawdown I have held through, it has behaved like insurance, because the won tends to weaken at exactly the moments global markets get uncomfortable — the same instinct that pushes money into dollars pushes it out of the won.
Monday had a policy layer on top of that pattern. The next Fed meeting is being framed as a tough battle for Warsh as the Fed girds for an expected rate hike — a fight over votes rather than a settled direction. A central bank that markets expect to tighten is a central bank whose currency gets bought, and that is a second reason the dollar held up while the assets priced in it did not.
When the Cushion Is Not There
The problem with insurance you never bought is that you never read the terms. The dollar is not a safe asset in any permanent sense. It is a safe asset when the trouble is somewhere else. When the trouble is the United States itself — a fiscal scare, a credit event inside its own system, a policy surprise that makes foreign money question the currency rather than run toward it — stocks fall, and the dollar falls with them. That is the day the losses actually compound. The equity is down, and the dollars that are left buy fewer won.
The won’s role in this arrangement is worth stating precisely. It is not a neutral home currency the way the dollar is for a US investor. It is itself a risk asset in the eyes of the people who move money across borders. That is why the cushion exists at all, and also why it is not something to feel good about — the same characteristic that softens my US drawdowns is what makes everything else I own here vulnerable at the same moment.
There is no rule saying the uncomfortable configuration cannot happen. It is simply rarer than the comfortable one, and repetition quietly edits rare events out of people’s thinking. If the currency has cushioned nine drawdowns in a row, the tenth one starts to feel structurally impossible — and the position has usually grown in the meantime, precisely because it kept behaving well.
There is a structural reason the comfortable version keeps showing up. Korea has been the lower-yielding side of this pair for a while. The Bank of Korea’s base rate stood at 3.00% as of September 12; the US 10-year Treasury yield closed Monday at 4.96%, down 1.4 basis points on the day. Those are different instruments at different maturities, so the distance between them is not a carry number anyone trades on. What it shows is which way the pull runs, and it has run one way long enough for the cushion to start looking like a rule. That is support for the cushion, not a guarantee of it. Yield advantages narrow, and they tend to narrow faster than portfolios get rebalanced.
What the Currency Does to the Tax Number
There is one more place this shows up, and it is specific to holding the shares directly rather than through a Korea-listed fund. As of 2026, in my case, a US stock sale is translated into won on both ends — what I paid and what I received — so the exchange rate is not a separate line to think about afterward. It is already inside the gain being taxed. A year in which the won weakens does not only flatter the account balance; it enlarges the taxable gain itself. Anyone weighing the Two Ways to Buy the S&P 500 from Korea is choosing a currency exposure as well as a product.
So the honest way to hold a dollar position from Seoul is neither to assume the currency is a hedge nor to assume it isn’t. It is to notice which question the market is answering on a given day. Monday it was answering where is safety, and the answer was the dollar. The days worth preparing for are the ones where the question becomes is the dollar safe, because on those days the answer arrives on both sides of the account at once.
Rate data from the Bank of Korea’s Economic Statistics System (ECOS). Figures are as of 2026. Korean tax rules change, sometimes yearly. This is my own experience as an individual investor, not tax advice.