Bid Price

The bid price is the highest price a buyer in the market is willing to pay for a currency pair at any given moment. When you sell (go short) a currency pair, you execute at the bid price. It's always the lower of the two prices quoted for any pair.

The bid price fluctuates constantly during market hours as buy orders flow in and out. During the London-New York overlap, bid prices on major pairs change multiple times per second. The speed and frequency of these changes reflect the depth of liquidity available at any moment.

For practical purposes, the bid matters most when you're closing a long position or opening a short one. If you bought EUR/USD and want to close the trade, your exit price is the current bid. The difference between the ask you paid to enter and the bid you receive on exit (minus any price movement) determines your profit or loss.