Definition of 'Best Bid' The highest quoted bid for a particular trading instrument among all those offered by competing market makers. The best bid is effectively the highest price that an investor is willing to pay for an asset. A bid is an offer made by a trader, investor or other industry professional to purchase a security. The bid specifies both the price that the buyer is willing to pay and the quantity of the security that is desired. Bid also refers to the price at which a market maker is willing to purchase a security. Best bid is the opposite of best ask.

Investopedia explains 'Best Bid' The National Best Bid and Offer (NBBO), which refers to the Securities and Exchange Commission (SEC) requirement, are the bid and ask prices that traders and investors typically see. They are required by the SEC to be the best bid and ask prices available to customers. Active traders, short-term traders and day traders often study Level 2 quotes that include all the bids and asks for a particular trading instrument. The NBBO is continually updated throughout the trading session so that customers have access to these prices.