Why the U.S. Sold Euros, Not Dollars: 5 Secrets Behind Defending Long-Term Rates

 

Why Did the U.S. Sell Euros Instead of Dollars? The Hidden Goal Behind the U.S.–Japan Deal

One of the most subtle yet important stories in markets right now is the behind-the-scenes battle over U.S. long-term interest rates. On the surface it looks quiet, but underneath, the U.S. Treasury, the Federal Reserve, and even Japan are running a carefully coordinated play. The key question is this: why did the United States sell euros rather than its own currency, the dollar? 🤔

Long-term interest rates — think of the 10-year Treasury yield — act as a benchmark that shapes government borrowing costs, mortgage rates, and corporate investment. When these rates spike, U.S. government interest expenses balloon, so Washington has an urgent incentive to keep them contained.

🔹 Card 1 — Selling Euros to Buy Yen

The U.S. Treasury used its Exchange Stabilization Fund (ESF), roughly $200 billion in firepower, to sell euros and buy yen. As a result, the dollar-yen rate fell rapidly from 164 on July 31 to 155, and now hovers around 158. Why sell euros instead of dollars? Because dumping dollars would shake the dollar's value and could trigger foreigners to sell off their U.S. Treasuries — which pushes yields up. By sacrificing a third currency, the euro, the U.S. defended the yen without shooting itself in the foot. 💱

🔹 Card 2 — Putting Out Fires with FIMA Repo

The FIMA Repo is a facility that lets foreign central banks pledge their U.S. Treasuries as collateral and borrow dollars from the Fed. This lets them raise dollars without dumping Treasuries on the open market, acting as a safety valve against a bond sell-off. Discussions are underway to raise this limit to around $60 billion. 🏦

🔹 Card 3 — The Fed's Quiet Coordination

From January to July, the Fed bought about $250 billion in short-term Treasuries — $160 billion in net purchases and $90 billion in reinvestments. By concentrating on short-term paper, it delayed the supply of long-term bonds to the market, softening upward pressure on long-term yields. 🔬

🔹 Card 4 — Stablecoins as a New Source of Demand

Stablecoins pegged to the dollar or yen buy large amounts of short-term U.S. Treasuries and money market funds (MMFs) as collateral. The bigger stablecoins grow, the deeper the new demand base for short-term U.S. debt becomes — supported by legislation such as the GENIUS Act and the CLARITY Act. 🪙

🔹 Card 5 — Easing Bank Regulation

In April, the Supplementary Leverage Ratio (SLR) was eased, Basel III risk weights on Treasuries were adjusted from 100% to 65%, and the GSIB capital surcharge on large banks is being reviewed. In short, banks are being cleared to hold more U.S. Treasuries with less burden — and more buyers means steadier yields. 🛡️

🔹 What to Watch

All five cards point to one goal: preventing a spike in U.S. long-term rates by any means available. For investors, the takeaway is to watch Treasury yields, the dollar index, and the yen exchange rate as an interconnected system. 📈

❓ FAQ

Q1. Why did the U.S. sell euros instead of dollars? A. Selling dollars directly would weaken the dollar and risk triggering foreign sell-offs of U.S. Treasuries, so the U.S. sold euros as a lower-side-effect alternative.

Q2. What is the FIMA Repo? A. It's a facility where foreign central banks borrow dollars from the Fed using U.S. Treasuries as collateral, serving as a buffer against bond dumping.

Q3. What is the term premium? A. It's the extra yield investors demand for holding longer-dated bonds; when it rises, long-term rates climb.

Q4. How are stablecoins connected to U.S. rates? A. Stablecoins buy short-term Treasuries as collateral, so as they grow, demand for U.S. debt rises, helping stabilize rates.