The relationship between the prices of calls (call options), puts (put options), and futures (futures contracts) on the same underlying asset. If the parity is violated, traders could earn an arbitrage profit. The parity relations for same month and same strike futures and options vary according to trading strategies. For example, the following parity relations are usually used by traders:

Long call = long put and long futures

Short call = short put and short futures

Long put = long call and short futures

Short put = short call and long futures

With a few assumptions, futures can be replaced by forwards (the so-called forward parity or call-put-forward parity would result).

It is also known as call-put-futures or put-call-futures parity (put-call-futures).

For more, see: futures parity relations.