Dealing spread refers to the difference between the bid and ask price of a financial instrument in a market. It is a form of transaction cost that traders have to pay when entering or exiting a position. The bid price is the highest price that a buyer is willing to pay for a particular instrument, while the ask price is the lowest price that a seller is willing to accept for the same instrument. The difference between the two prices represents the dealing spread, which is essentially the commission paid to the broker or market maker for facilitating the trade. The dealing spread can vary depending on various factors, such as market volatility, liquidity, and trading volume.