Hedge Funds Ramp Up Biggest Yen Short Since 2007 as USD/JPY Climbs to a 40-Year Peak

The yen is capping a brutal year, and some of Wall Street's most aggressive players are positioned for more downside. CFTC figures show leveraged funds have pushed net short yen bets to nearly 138,000 contracts, the most bearish stance since 2007. Pressure on the currency has intensified as USD/JPY trades around 162, a level last seen in 1986. The rate gap remains the market's core driver: Japan's policy rate is roughly 0.5% to 0.75%, while U.S. Treasuries yield about 4%. That spread of around 3.25 percentage points keeps the carry trade attractive, encouraging investors to fund in yen and reinvest in higher-yielding dollar assets. Major banks are also leaning into the trend. Goldman Sachs lifted its USD/JPY target to 165. Options pricing points in the same direction, implying a 72% probability the pair reaches 165 by mid-2027. Japan's intervention playbook is looking less effective. In April and May 2026, authorities spent more than $73.5 billion in the FX market to support the yen, yet the currency continued to weaken. The Bank of Japan has nudged rates up from negative territory to the current 0.5% to 0.75% range, but the pace still lags far behind U.S. levels. Earlier intervention episodes in 2022 and 2024 followed a familiar arc: brief rebounds, then renewed selling. Crypto traders have reason to watch the yen closely. In August 2024, a surprise BOJ hike sparked a sharp yen rally that rippled across global markets, sending Bitcoin lower alongside equities as leveraged positions were forced out. With shorts now at their most crowded since 2007, the risk of a violent reversal is rising. Potential triggers include an unexpected BOJ rate hike, a sudden weakening in U.S. economic data that pushes Treasury yields down, or more credible verbal intervention than in prior rounds. Any of these could set off rapid short-covering in the yen, amplifying cross-asset volatility—a dynamic that often hits crypto especially hard due to its sensitivity to leverage and liquidity.