The difference between the bid and ask prices for a particular tradable asset (stock, bond, etc..). For example, if a stock is bid at $50 and and offered at $51, the spread is $1. This spread widens and narrows reflecting the supply and demand for the asset being traded. Usually a large spread is an indication of inactive trading of the asset.

It is also used to denote the difference between the issue price and current price of a security, such as a bond.

Compare with: spread (options), spread (futures), spread (commodities), spread (forex), spread (underwriting).