Yen Carry Trade: Why Japan Moves US Markets

The yen carry trade is a strategy where investors borrow in Japanese yen, where interest rates have been near zero for decades, and invest the money in higher-yielding assets elsewhere — US Treasuries, stocks, or other currencies. It works as long as the yen stays weak and Japanese rates stay low. When either changes quickly, investors rush to repay their yen loans, and that forced selling can ripple into markets around the world, including US stocks.

This guide explains how the carry trade works, why Japan's interest rates matter so much to global markets, and what it means for an ordinary US portfolio.

How the Carry Trade Works

The idea is simple: borrow where money is cheap, invest where it pays more, and keep the difference — the "carry."

A simplified example:

1. An investor borrows yen at an interest rate close to 0%.
2. They convert the yen into dollars and buy US Treasury bills yielding around 4% or 5%.
3. As long as the exchange rate stays put, they earn the gap between the two rates.

The catch is currency risk. The loan has to be repaid in yen. If the yen strengthens against the dollar, each dollar buys fewer yen, and the investor needs more dollars to repay the same loan. A sharp enough rise in the yen can wipe out years of interest income in a few days. Many carry trades also use leverage, which magnifies both the profits and the losses.

Why Japan's Rates Were So Low for So Long

Japan spent much of the past three decades fighting the opposite of inflation: falling or flat prices. To encourage borrowing and spending, the Bank of Japan (BOJ) kept short-term rates at or below zero, bought huge amounts of government bonds, and from 2016 capped long-term bond yields through a policy called yield curve control.

That made the yen one of the cheapest currencies in the world to borrow, and the carry trade grew enormous. In 2024 the BOJ began to change course: it ended negative interest rates and yield curve control in March, and raised rates again in July.

When the Carry Trade Unwinds

A carry trade unwinds when the conditions that made it profitable reverse — usually Japanese rates rising, US rates falling, or both. The gap narrows, the yen strengthens, and leveraged investors face losses at the same time.

To cut their risk, they sell the assets they bought with borrowed yen and convert the proceeds back into yen. That selling pushes asset prices down and the yen up further, which forces more investors to unwind. The process can feed on itself for days.

August 2024 is the clearest recent example. After the BOJ's July rate increase and a weak US jobs report, the yen jumped and the carry trade unwound quickly. On August 5, Japan's Nikkei 225 index fell about 12% in a single day — its worst day since the 1987 crash — and US stocks and volatility measures swung sharply as well. Markets recovered much of the drop within weeks, but the episode showed how a policy shift in Tokyo can move portfolios in New York.

Why Japan Matters to US Investors

Japan is the largest foreign owner of US government debt

Japanese investors and institutions hold around $1 trillion in US Treasuries, more than any other country. If higher yields at home make Japanese bonds more attractive, some of that money can come home, which puts upward pressure on US interest rates — and, in turn, on mortgage rates and bond prices here.

Japan's government debt is unusually large

Japan's public debt is more than twice the size of its economy, one of the highest ratios in the world. That debt has been manageable because the BOJ owns a large share of it and rates were near zero. As rates rise, the cost of servicing that debt rises too, which is part of why the BOJ moves cautiously and why markets react strongly to any hint of faster tightening.

Currency moves affect your international holdings

If you own Japanese stocks through a fund, your return depends on both the stock prices and the yen. A stronger yen boosts the dollar value of Japanese holdings; a weaker yen reduces it. Japan's government has also intervened in currency markets at times to slow the yen's decline, which can cause sudden moves.

What It Means for Your Portfolio

For most long-term investors, the carry trade is something to understand, not something to trade:

1. Expect occasional sharp, short-lived swings. Carry-trade unwinds tend to cause fast selloffs that often reverse. Selling in a panic usually locks in losses.
2. Know your international exposure. Total-market international funds hold Japanese stocks — Japan is one of the largest weights in developed-market indexes. You can see how a broad international fund fits alongside US stocks with our VTI vs VXUS comparison, or look at a Japan-only fund on our EWJ ETF page.
3. Watch bond duration. If Japanese money flows home and US yields rise, long-term bond funds fall the most. Our BND vs TLT comparison shows the difference between a total bond fund and a long-term Treasury fund.
4. Avoid leverage you don't fully understand. The carry trade's danger comes from borrowed money. The same is true of margin accounts and leveraged ETFs held by individual investors.

How Fed policy fits into this picture is covered in our guide on how Fed interest rates affect your money: the carry trade is most vulnerable when US rates are falling while Japan's are rising.

Frequently Asked Questions

What is the yen carry trade in simple terms?

Borrowing yen cheaply and investing the money in higher-yielding assets elsewhere, keeping the difference in interest rates — as long as the yen doesn't strengthen.

Why does a stronger yen hurt the carry trade?

The loans must be repaid in yen. When the yen rises, borrowers need more of their dollars or other currencies to repay the same amount, which can erase their interest income and cause losses.

Can the carry trade cause a stock market crash?

It can contribute to sharp selloffs, because leveraged investors sell assets quickly to repay yen loans. The August 2024 unwind caused one of the biggest single-day drops in Japanese stocks in decades. Such episodes have usually been short-lived, but they can be severe.

How big is the yen carry trade?

No one knows exactly, because it's spread across banks, hedge funds and other investors in many forms. Estimates vary widely, from hundreds of billions to several trillion dollars, depending on what's counted.

Should I invest in Japanese stocks?

Japan is a major developed market, and most diversified international funds already include it. Whether to add more depends on your goals and how much currency risk you're comfortable with. A broad international fund is a simpler way to get exposure than betting on one country.

This guide is for general education and isn't personal financial advice.