"Asia is slow" gets repeated like gospel by people who trade EURUSD and nothing else. For EURUSD, GBPUSD and USDCHF, it's mostly true. Spreads are wider and movement is limited, aside from the occasional data spike.
Switch to AUDJPY, NZDJPY, USDJPY, AUDUSD or USDCNH and the picture changes. Those pairs have home-market participants awake, with real flow from corporates, real-money accounts and central banks. Data from Australia, New Zealand and Japan lands in these hours, and each release brings its own burst of activity.
What changes is the character of the movement. Ranges are tighter but cleaner, and often anchored by fixing times. The Tokyo fix at 9:55 JST is the biggest recurring example, with USDJPY often drifting into it and pausing afterwards. Month-end and the gotobi days can add a directional lean.
For a scalper, the practical difference is pair selection. Trading the wrong pair at the wrong hour feels like a broken strategy when it's really a mismatch between the instrument and the session. The same setup that worked on EURUSD in London will fail on EURUSD in Tokyo and might work on AUDJPY.
Costs need a fair look too. AUDJPY at 1.5 pips in Tokyo can be a better deal than EURUSD at 1.2 in the same hour, because the move per minute is larger and the cost relative to range is smaller.
A few cautions apply. Liquidity thins out at the edges of the session, particularly the late Asian afternoon and the handoff to London. Holidays in Japan or Australia drain activity from the relevant pairs. And overnight moves in thin conditions can be violent, as the January 2019 episode showed.
A short experiment is enough to get a feel. Plot the average one-minute range and the average spread for a handful of pairs from 22:00 to 08:00 GMT. The pairs that stand out as having reasonable range relative to cost are the ones worth watching.
Which pairs have turned out to be the real performers during Asia, and which ones were an expensive mistake?