The Rhyme: U.S. Buys Yen for First Time in 28 Years & Its 1998 Echo

"History doesn't repeat… but it rhymes." — Mark Twain

The United States and Japan confirmed a joint currency intervention last Friday, buying yen together for the first time since the Asian Financial Crisis of 1998. Bank of Japan data suggested authorities sold as much as $58.97 billion to arrest the yen's slide to a 40-year low of 163.99 per dollar, and Treasury Secretary Scott Bessent posted that he would not hesitate to do it again. The dollar dropped to as low as 155.20 yen before settling near 157 on Monday, while U.S. stocks rallied and the 10-year Treasury yield fell to 4.68%. The last time Washington and Tokyo did this together, Robert Rubin was running the Treasury, Bill Clinton was packing for a trip to Beijing, and a fund called Long-Term Capital Management was two months away from blowing up the world.

USD/JPY: 163.99 → 155.20 (intervention) | Intervention size: ~$58.97B | Fed funds: 3.50–3.75% | BOJ rate: 1.00% | 10Y yield: 4.68% | S&P 500: 7,600 | Carry trade est.: $4–20T

Robert Rubin had spent twenty-six years at Goldman Sachs before he walked into the Treasury Department, and for most of those years he had traded currencies. He knew what a falling yen looked like. He also knew what it looked like when everyone on a trading floor decided the same trade was a sure thing. By mid-June 1998, the yen had been sliding for months against the dollar, dragged down by Japan's deepening recession, a banking system choked with bad loans, and an interest rate near zero that made the yen the cheapest funding currency on earth. Traders borrowed yen at practically nothing, converted it to dollars, and parked it in U.S. Treasuries or emerging-market bonds paying five, six, seven percent. The spread was free money. Until it wasn't.

On the morning of June 17th, the yen hit 146 to the dollar, an eight-year low, and the phones started ringing from Beijing. Chinese officials told the Financial Times they had drawn up contingency plans to devalue the renminbi if the yen kept falling. That was the nightmare scenario. A Chinese devaluation would set off another wave of competitive devaluations across Asia, just as the region was crawling out of the wreckage of the Thai baht collapse, the Indonesian rupiah freefall, and the South Korean won crisis. President Clinton was scheduled to fly to China in eight days. Rubin decided he had seen enough.

The New York Fed's trading desk got the order that afternoon. Sell dollars, buy yen. The Fed and the Exchange Stabilization Fund split the cost, and when the dust settled, Washington had spent $833 million. It was the first time the Clinton Administration had ever intervened to strengthen the yen. The currency bounced, briefly, from 146 toward 136. Traders on every major desk in London and New York paused for about seventy-two hours. Then they went right back to selling.

By August, the yen had slipped back to 147, weaker than it was before the intervention. Then Russia defaulted on its sovereign debt on August 17th. The contagion ripped through every carry trade on the planet. Long-Term Capital Management, a Connecticut hedge fund run by a former Salomon Brothers trader and two Nobel laureates, had taken the yen carry trade and multiplied it by twenty-five. When Russia blew, LTCM's positions went with it. The New York Fed organized a $3.6 billion private-sector bailout later that month, and Greenspan cut rates three times in seven weeks, taking the fed funds rate from 5.50% to 4.75%. On October 7th, the yen moved from 134 to 120 against the dollar in a single session, a 10% swing that the Bank for International Settlements called the largest one-day yen move ever recorded. The carry trade didn't just unwind. It detonated.

The S&P 500 had already fallen 19.3% from its July 17th peak by the end of August. It retested the lows on October 8th. But Greenspan's rate cuts worked, because in 1998 the Fed had room. The fed funds rate started at 5.50%, and there was a long way down. By year-end, stocks had recovered every penny. The lesson was clear and simple: intervention alone doesn't fix a carry trade. Something has to break the underlying spread. In 1998, that something was a Russian default and three emergency rate cuts.

Both times, the world's two largest economies teamed up to fight a currency they had no structural ability to fix, because the interest-rate spread that was killing the yen was a direct product of their own monetary policies.

Here is what happened after June 17, 1998, step by step. The intervention bought about seventy-two hours of calm. Then the yen started sliding again. By early August it was back at 147, worse than before Rubin picked up the phone. Russia's default on August 17th was the match. The carry trade positions that had been quietly rebuilt in July were suddenly underwater, and the unwind started slowly, then all at once. LTCM lost $4.6 billion in less than four months. The S&P 500 dropped 19.3% between July 17th and August 31st. The New York Fed spent the last two weeks of September calling fourteen banks to arrange a private bailout. Greenspan delivered his first cut on September 29th, his emergency inter-meeting cut on October 15th, and a third cut on November 17th. The yen snapped from 134 to 120 on October 7th as carry trades unwound in a single afternoon.

The investors who made money in late 1998 were the ones who understood one thing: the intervention was never the fix. It was the warning. Rubin's $833 million didn't stop the yen from falling. What stopped it was a crisis large enough to force the Fed to cut rates and close the spread that funded the carry trade in the first place. The yen's real bottom came not when governments intervened, but when the carry trade's economics broke.

Now apply that to today. Bessent has spent $58.97 billion and the yen is still above 155. The BOJ is at 1.00%, the Fed is at 3.50–3.75%, and the spread is roughly 250 basis points. That spread will not close through intervention. It will close one of two ways: either the BOJ hikes aggressively into a weak Japanese economy, or the Fed cuts into what might be rising inflation. Neither central bank wants to move. Both may be forced to. In 1998, the forcing event was Russia. In 2026, the list of candidates is longer: an Iran escalation, a Treasury market accident, a carry trade unwind triggered by the BOJ's next move, or a U.S. labor market that added 172,000 jobs last month and might print something worse on Friday.

The pattern says the intervention is the beginning of the story, not the end. In 1998, the real move came three and a half months after Rubin acted. The smart money used that window not to relax, but to reduce exposure to everything funded by cheap yen, quietly, before the October snap.

The edge: In 1998, joint intervention preceded the real crisis by 92 days. The carry trade rebuilt itself in July, broke catastrophically in October, and only ended when the Fed cut three times. Today, the Fed can't cut. The intervention clock started Friday. Count the days.

Friday's nonfarm payrolls report (consensus: 91,000) arrives with the yen carry trade already cracking. One year ago almost to the day, on August 5, 2024, a weak U.S. jobs number combined with a BOJ rate hike triggered the Nikkei's worst single-day crash since 1987 and a 3% S&P selloff. The carry trade rebuilt itself after that scare. The question is whether it survives a second one.