A put option is a financial market derivative instrument that gives the buyer (i.e the holder of the option) the right to sell an underlying asset at a predetermined price before or on a specified date. This is also called a put; the term is derived from the fact that the holder has the right to 'put up for sale' the underlying security. Buying a put option is interpreted as a negative sentiment about the future value of the underlying securities because it allows the buyer to profit if the price of the underlying securities declines.