Yen at 162 threatens global bonds as JGB yields top 4%

Japan's currency weakness and climbing long-end government bond yields are creating a spillover risk that could push up Treasury, gilt and bund yields globally, according to OCBC strategists.

"Perceptions that the BOJ is behind the curve is fueling depreciation pressure on the yen," Moh Siong Sim, currency strategist at OCBC, said. He expects the yen to remain under pressure in the near term.

The 10-year JGB yield held at 2.830% while the 30-year yield rose 1 basis point to 4.085% ahead of the Finance Ministry's auction of about 600 billion yen ($3.7 billion) of 30-year debt. The yen traded near 162.14 per dollar, just above last week's low of 162.84 — the weakest since 1986.

If JGB yields keep climbing, global yields could be pushed higher still, OCBC said, noting that upward pressure on Treasuries, gilts and bunds may already be underway. Further yen depreciation would likely weigh on regional Asian currencies, particularly the won and the baht.

The 30-year JGB auction drew attention from real-money investors rather than fast-money speculators, according to SMBC Nikko Securities. "The 30-year issue does not look particularly attractive from a relative-value standpoint, its high outright yield stands out," Miki Den, senior Japan rates strategist at SMBC Nikko Securities, said in a research report.

Goldman Sachs revised its USD/JPY forecast sharply upward, now projecting the pair at 162 in three months, 163 in six months and 165 within a year — a jump from its previous target of 155. The bank cited persistent US yield advantages and Japan's fiscal strains as key drivers. J.P. Morgan's 2026 target of 164 aligns loosely with Goldman's view, while ING projects a dramatically different outcome at 153, a gap of roughly 12 yen between the two forecasts.

The divergence hinges on the Bank of Japan's policy path. Governor Kazuo Ueda has signaled willingness to normalize policy, but each step has been measured. Between April and May 2026, the Japanese government spent over 11 trillion yen intervening in currency markets with limited lasting effect. Former BOJ policymaker Sayuri Shirai said on June 23 that the yen could weaken toward 163-165 if the Federal Reserve raises rates this year.

On the US side, Fed Chair Kevin Warsh said last week that anyone thinking the central bank may go easy on inflation could be "disappointed." The dollar index hit a 13-month peak last week before retreating as expectations for a July rate hike faded. City Index strategist David Scutt noted that Fed policymaker Christopher Waller tends to be a "lead indicator for the direction of travel on the FOMC," urging traders to watch for his signals.

The Carry Trade Risk

The yen's persistent weakness has supercharged carry trades — borrowing in low-yielding yen to invest in higher-yielding assets elsewhere. These trades have channeled capital into risk assets including US equities and cryptocurrencies. The July 2024 carry trade unwind offers a cautionary case: a modest BOJ rate hike triggered yen strengthening that forced rapid deleveraging across global markets, with Bitcoin dropping sharply as risk appetite evaporated. The last time USD/JPY moved below 158 in a single session, it preceded a 10% correction in the Nikkei 225 over the following two weeks.

What to Watch

Traders should monitor any hawkish shift in BOJ rhetoric, currency intervention by Japan's Ministry of Finance, and sharp moves in USD/JPY below 158 as potential early warnings of a broader unwind. The Federal Reserve's next move also matters: if the Fed cuts rates more aggressively, the yield differential narrows, the yen strengthens, and carry trades unwind — pressuring risk assets from multiple directions simultaneously. The FOMC minutes from the June meeting, due Wednesday, may offer further clues on the rate outlook.

This article is for informational purposes only and does not constitute investment advice.