• London trading session: the London trading session opens at 3:00am EST and closes at 12:00pm EST. • New York trading session: the New York trading session opens at 8:00am EST and closes at 5:00pm EST. The over-lap of the London and New York trading sessions between 8am and 12pm EST is typically the best time to trade, because this is when the world’s two most active trading centers cross; as the London session is closing the New York session is opening.