Intervention Fails to Reverse Yen Weakness: Carry Trade Remains Unchecked

The USD/JPY currency pair has been trading near its 159 level for some time now, and it's clear that recent intervention efforts have failed to reverse yen weakness. The pair is up 0.06% from Friday's close of 158.98, but the monthly figures show a currency that has stabilized without recovering. Over the past thirty days, the yen has strengthened by 2.85%, largely due to the intervention shock.

The coordinated intervention between Japan and the United States on August 1 was significant, with the pair dropping sharply from above 164 toward the mid-156 area within hours. However, three weeks later, USD/JPY trades at 159.08, having erased roughly half of the operation's effect. The pattern is consistent across every episode: intervention breaks momentum, produces a violent short-term move, and fails to change the level within weeks.

The August operation did not address the underlying issues driving yen weakness, such as the wide US-Japan interest rate gap or inflationary pressure created by expensive energy and a weak currency. It also handed the carry trade a discounted entry, turbo-charging the trade for fundamental and long-term investors rather than deterring it.

Any future intervention that produces a meaningful yen rally will attract domestic buying, funding the next leg of yen weakness. Tokyo can only escape this by making the carry unattractive, which requires the rate gap to narrow substantially rather than marginally.