# Payoff at expiry for the purchase of a put option

## Description

Formula for calculating the payoff of a long position in a put option.

## Formula

\[ R_{lp}=max\left ( -P+(K-S_{T}),-P \right ) \ \]

## Legend

\(K\ \) | Option strike price |

\(P\ \) | Value of the option premium |

\(S_{T}\ \) | Price of the underlying at expiry date T of the option |

## Additional information related to this formula

### Related definitions:

•