In financial markets, the bid/ask spread indicates liquidity and market depth. The bid price is the maximum price that a buyer is prepared to pay for a security, while the ask price is the minimum a seller is willing to accept. The difference between these two prices is known as the spread, which can impact trading costs; narrower spreads suggest higher liquidity and lower trading costs, while wider spreads may suggest lower liquidity and higher costs. This concept is vital in both traditional finance and decentralized finance (DeFi) environments, where order books may be used to facilitate trades.