Japan has spent more money defending its currency in the past month than ever before.

The country’s Finance Ministry says it used 15.3993 trillion yen — roughly $96.5 billion — between July 30 and August 26 to support the yen after it fell to its weakest levels in roughly four decades.

That would already be a major story for Japan.

But the reason global markets are paying attention is that the consequences do not stop in Tokyo.

Treasury Secretary Scott Bessent warned that a disorderly collapse in the yen could force investors around the world to unwind large financial positions, disrupt bond markets and ultimately raise borrowing costs for American households and businesses.

That is because the yen has spent years at the center of one of the most important trades in global finance.

Japan kept interest rates extremely low for decades.

Investors could borrow cheaply in yen and use that money to buy higher-yielding assets elsewhere — including U.S. Treasuries, corporate bonds and stocks.

That strategy is commonly known as the yen carry trade.

It works well when the yen is stable.

It becomes dangerous when the currency begins moving violently.

If the yen suddenly strengthens, investors who borrowed in yen can face rapidly growing losses and may be forced to sell other assets to repay those loans.

If the yen collapses instead, Japan faces higher import costs, more inflation and pressure on households and businesses.

That puts Tokyo in a difficult position.

Japan cannot simply allow the yen to fall indefinitely.

But defending it on this scale also has consequences.

The July intervention was particularly unusual because the United States joined Japan in buying yen, a rare example of coordinated currency intervention between the two governments.

Japan’s Finance Ministry later confirmed that the July 31 action was carried out together with the U.S. Treasury.

The government has also said it is prepared to intervene again if markets become disorderly.

The yen had weakened to around 164 per dollar before the intervention, its lowest level in about 40 years. The operation temporarily strengthened it, but the currency has since drifted back toward the 160 level.

That is why the pressure has not disappeared.

Japan is also increasingly expected to raise interest rates again.

The Bank of Japan lifted its benchmark rate to 1% in June, and economists now expect another increase could come as soon as September.

Higher Japanese rates would help support the yen.

But they could also encourage Japanese investors to keep more money at home instead of buying U.S. bonds.

That creates another potential problem for Washington.

Japan is one of the largest foreign holders of U.S. Treasury securities.

If Japanese investors find domestic bonds increasingly attractive, demand for U.S. government debt could weaken at exactly the moment Washington needs enormous amounts of financing for a federal debt load that has already surpassed $40 trillion.

Less demand generally means Treasury must offer higher yields to attract buyers.

And higher Treasury yields eventually filter through to mortgages, corporate loans, commercial real estate and other borrowing costs.

That is the connection Bessent is warning about.

A currency problem in Japan can become a financing problem in the United States.

For businesses and investors, the bigger lesson is that currencies are no longer moving quietly in the background.

Governments are intervening directly.

Central banks are changing rates.

And enormous pools of capital can move from one country to another very quickly when the economics change.

Japan has already spent nearly $100 billion trying to stabilize the yen.

If the currency remains under pressure, the next intervention could be even larger.

And the biggest question for Americans may ultimately not be what happens to the yen itself.

It may be what happens to U.S. borrowing costs if one of the world’s largest sources of capital begins bringing more of its money home.

JBizNews Desk | Tokyo / Washington

© JBizNews.com All Rights Reserved. Reproduction or distribution without written permission is prohibited.