The Japanese yen has continued to weaken against the U.S. dollar even as the Bank of Japan moves toward tighter monetary policy, according to a recent analysis from BNP Paribas. The gap between policy expectations and actual currency performance points to continuing structural pressure on the yen.

Bank of Japan Tightening Has Not Lifted the Yen

The Bank of Japan has taken steps to normalize its long-running ultra-loose monetary policy, including adjustments to its yield curve control policy and signals that potential interest rate increases could follow. In traditional currency-market models, monetary tightening can support a domestic currency by making local assets more attractive and encouraging capital inflows.

However, the yen has not strengthened in the way such models might suggest. BNP Paribas strategists said several forces are outweighing the impact of the Bank of Japan’s gradual policy shift.

A central factor is the still-wide interest rate differential between Japan and the United States. The Federal Reserve’s aggressive rate-hiking cycle has kept U.S. yields elevated, increasing the relative appeal of dollar-denominated assets for global investors. Even with the Bank of Japan moving toward normalization, Japanese rates remain near zero, leaving little yield advantage for yen-based assets. That gap also keeps the yen vulnerable as a funding currency in carry trades, where investors borrow in lower-yielding currencies to buy higher-yielding assets elsewhere.

Structural Pressures Continue to Weigh on the Currency

BNP Paribas also pointed to broader structural factors behind the yen’s weakness. Japan’s persistent current account surplus has been narrowing, reducing a traditional source of yen demand. At the same time, Japanese institutional investors continue to seek higher returns overseas, creating steady capital outflows that add downward pressure on the currency.

The bank’s analysis suggests that market participants see the Bank of Japan’s tightening as incremental and not sufficient to close the gap with the Federal Reserve’s policy stance. As long as the U.S. economy remains resilient and inflation remains sticky, BNP Paribas said the dollar is likely to retain its relative strength advantage.

The currency move matters beyond foreign exchange trading because a weaker yen can raise the local-currency cost of imported goods, including energy and food, while also supporting the yen value of overseas earnings for some Japanese exporters. That mixed impact helps explain why exchange-rate shifts remain closely watched by policymakers, companies, and households.

USD/JPY Remains Driven by U.S. Rates

For the foreign exchange market, the analysis indicates that USD/JPY may continue to trade with an upward bias even as the Bank of Japan takes limited steps toward policy normalization. The currency pair has already tested multi-decade highs, and BNP Paribas sees few catalysts for a sustained yen reversal in the near term.

The bank said the main driver of USD/JPY remains the Federal Reserve’s interest rate stance and the resilience of U.S. economic data. Bank of Japan policy announcements remain important, but U.S. economic indicators and Federal Reserve commentary continue to have a dominant influence on the pair’s direction.

BNP Paribas said a meaningful reversal in yen weakness would require a sharp narrowing of the U.S.-Japan rate differential, a major shift in global risk sentiment, or more aggressive action from the Bank of Japan. Based on current data and central bank guidance, the analysis said none of those factors appear imminent.

The yen’s weakness despite Bank of Japan tightening highlights the influence of U.S. monetary policy and global yield dynamics in currency markets. Until the interest rate gap narrows significantly, the yen may remain under pressure, challenging conventional expectations about how central bank policy normalization affects exchange rates.