The yen experiences its worst drop in four decades

The yen hit 163.23 per dollar on July 21, 2026, its lowest level since December 1986. This historic drop exposes the limits of a currency weakened by negative real rates and revives the narrative of bitcoin as a scarce asset.

In brief

• The yen fell to 163.23 per dollar on July 21, 2026, an unprecedented level in nearly 40 years.
• Rising oil prices, U.S. yields, and weak Japanese real rates have intensified the pressure.
• The limited supply of Bitcoin fuels its monetary narrative, without eliminating its price risk.

The yen crosses 163, a threshold forgotten for four decades

The 160 threshold had already put Tokyo on alert. A month after the Bank of Japan raised its rates to their highest level since 1995, the yen resumed its decline and crossed 163 per dollar. The movement confirms that the Japanese monetary tightening is not sufficient, at this stage, to bridge the gap with U.S. yields.

According to Reuters, the Japanese currency reached 163.24 during trading in New York on July 21, its weakest level since the end of 1986. On the same day, the yield on the U.S. ten-year Treasury bond hit 4.64%, while the thirty-year yield rose to 5.15%. These levels supported the dollar.

Oil added further pressure. Brent reached $92.67 per barrel in Asia on July 22, amid escalating tensions between the U.S. and Iran. Japan imports most of its energy. Higher oil prices increase its external bill and weaken the yen, while the dollar benefits from its status as a safe haven.

Tokyo threatens to intervene, but the market watches the rates

The Japanese government can buy yen to curb a disorderly decline. However, traders doubt the lasting effect of an intervention if the interest rate gap with the United States remains so wide.

Tokyo has already conducted record yen purchases in April and May 2026, when the dollar had surpassed 160 yen. Their effect has dissipated. Japan's Finance Minister, Satsuki Katayama, has again promised "decisive" action in the event of excessive movements, without announcing an official threshold.

Japanese real rates remain negative, as inflation still exceeds the available monetary yield. HSBC therefore estimates that the dollar-yen pair could mainly trade between 160 and 165, with occasional interventions to limit excesses.

The Bank of Japan, however, retains some maneuvering room. A Reuters survey published on July 23 indicates that 86% of economists surveyed anticipate another rate hike in 2026, possibly as early as October. In contrast, 95% of them believe that the central bank will not move during the current quarter.

Bitcoin gains an argument, not a risk-free status

The fall of the yen strengthens the argument for scarce assets: a central bank cannot increase the maximum supply of bitcoin, which its protocol caps at 21 million units. A saver exposed only to cash thus suffers a loss of purchasing power of their currency when prices rise or the exchange rate falls.

However, this comparison has its limits. The yen serves as a unit of account, a means of payment, and a store of value in an economy worth several trillion dollars. Bitcoin remains a volatile global asset whose price depends on liquidity, regulation, and risk appetite.

In summary, the yen concentrates three tensions: negative real rates, a heavier energy bill, and doubts about public finances. The upcoming decisions of the Bank of Japan, a potential intervention from Tokyo, and bitcoin's sensitivity to Brent will determine the future. This analysis does not constitute financial advice: scarcity does not eliminate volatility.