Every Tokyo business day, Japanese banks set a reference rate at 09:55 local time (00:55 UTC). Importers and exporters use it for their currency transactions, which can create predictable flows.
What is often observed:
USDJPY demand before the fix, as importers buy dollars.
Stronger effects on the "gotobi" days — dates ending in 5 or 0 — when many Japanese companies settle payments.
Price frequently drifts toward the fix and partly reverses afterwards.
For short-term traders:
The window 00:30–01:00 UTC is a recognisable intraday pattern to test.
Effects are small compared with major data and can be overwhelmed by US yields or risk sentiment.
Month-end and gotobi days combined can produce larger moves.
Testing it is straightforward: compare the USDJPY move from 00:30 to 00:55 UTC on gotobi days with other days over a year or two of data.
Has anyone tested gotobi days or the Tokyo fix on USDJPY?
I only mark the Tokyo fix on gotobi dates ending in 5 or 0, and I ignore the pattern on ordinary days. Over a twelve month sample the 00:30 to 00:55 UTC drift on USDJPY averaged about 8 pips on those dates versus roughly 3 on the rest.
The reverse after the fix is where I get most of the edge, not the run into it. Chasing the pre fix bid into a US yield spike has cost me more than it has paid.
Month end stacked on a gotobi day is the only time I widen the window to a full hour. Otherwise the move is too small next to spread and the chance of a risk headline.
I also skip the setup if overnight US data is scheduled inside that hour. The corporate flow story does not survive a surprise print.
Has your sample shown a cleaner post fix fade than a pre fix long? Both sides work about the same for me only when yields are quiet.
