Yen Carry Trade: Checking Unwind Signals for Crypto

The Bank of Japan raised its key rate by 25 basis points to 1.25 percent on Friday, September 18, 2026. That is the highest level in 31 years. Two days earlier, the US Federal Reserve had lifted its target range by the same amount to 3.75 to 4.00 percent. Two tightenings within three days, and the crypto market is still higher than the day before: Bitcoin was quoted at around $80,978 on the evening of September 18, 5.8 percent above its level 24 hours earlier, with Ether at around $2,613 and a gain of 6.5 percent (own query at CoinGecko on September 18, 2026 at about 18:52 UTC).

The short answer to the question this raises: a rate move by the Japanese central bank is only dangerous for crypto investors if it triggers an unwinding of yen-funded positions. That is precisely what failed to happen this time, and the reason can be read off a handful of figures you can look up yourself. This article explains which ones they are, and what to check on your own position while the tightening round continues.

What the Bank of Japan decided on September 18, 2026

The Japanese central bank raised the uncollateralised overnight call rate from 1.00 to 1.25 percent. The decision appears in the Bank of Japan's overview of monetary policy releases as Change in the Guideline for Money Market Operations under the date September 18, 2026. It is not this year's first move: the same list already shows a change to the same guideline for June 16, 2026. Some media reports on Friday spoke of the first increase of the year, which does not hold up against the central bank's own list of decisions. The defensible wording is the one Al Jazeera also uses: the first increase since June.