The London session refers to the trading hours of the foreign exchange market in London, which is one of the largest financial centers in the world. The London session typically starts at 8:00 a.m. GMT and ends at 4:00 p.m. GMT, overlapping with the end of the Asian session and the beginning of the New York session. During the London session, there tends to be a significant amount of liquidity and volatility in the market due to the high volume of trading activity. Many major currency pairs, such as EUR/USD and GBP/USD, often experience their highest trading volumes during the London session.