Japan Sold Treasuries to Fund Record Yen Intervention

Japan’s foreign securities holdings fell by a record $87.8 billion in August. This drop matches the scale of the largest currency intervention in Japanese history. Authorities spent approximately $98.6 billion, or 15.4 trillion yen, to support the yen through August 26. The source of these funds appears to be the sale of U.S. Treasury securities.

Total foreign-currency reserves declined by $94.6 billion to $995 billion at the end of August. The Ministry of Finance acknowledged that intervention contributed to this reduction. However, the ministry did not specify which assets were sold. Market data strongly suggests that short-dated U.S. Treasuries were liquidated to generate the necessary dollars.

Short-Dated Bonds Likely Sold

Reserve managers prioritize highly liquid assets for rapid conversion to cash. Short-term Treasuries offer this liquidity without causing significant market disruption. Estimates indicate that about 70 percent of Japan’s reserves are invested in U.S. government debt. Selling bonds with maturities of five years or less is the most logical step.

This strategy avoids pressure on long-term U.S. borrowing costs. Selling 10-year or 30-year bonds would conflict with American debt-management priorities. Washington has shown sensitivity to rising long-end yields. Concentrating sales at shorter maturities reduces this geopolitical and financial friction.

Record Intervention Scale

The August intervention was the largest monthly operation on record. It followed a sharp decline in the yen that pushed USD/JPY near four-decade extremes. The United States joined Japan in buying yen on July 31. This marked the first coordinated intervention between the two countries since 1998.

The joint action signaled alignment between Washington and Tokyo on preventing disorderly currency moves. Intervention of this magnitude creates a significant financing challenge. Japan must obtain foreign currency to purchase yen. Selling reserve assets provides a straightforward method to access these funds.

Reserves Remain Substantial

Japan retains nearly $1 trillion in foreign-currency reserves despite the spending. Foreign-currency deposits also declined by $6.9 billion during the period. The remaining reserve stock indicates substantial financial capacity remains. The FIMA Repo Facility offers additional access to up to $60 billion per day.

This facility allows Japan to intervene without selling physical securities. It provides a backup option for future currency operations. The current reserve levels ensure Japan can continue to defend the yen if needed. The market now focuses on the specific maturities of bonds sold in August.