The overlap of major financial centre trading hours: Sydney, Tokyo, London, and New York, each bringing distinct liquidity and volatility profiles.
The London session (08:00–17:00 GMT) is the most liquid, accounting for roughly 38% of daily volume. The London–New York overlap (13:00–17:00 GMT) is typically the most volatile and liquid window. Asian sessions see lower volume and tighter ranges on majors but can move JPY pairs significantly.
Traders match their strategies to the session: breakout traders focus on London open; range traders may prefer Asian hours.