PUT–CALL PARITY an important relationship between the prices of European put and call options that have the same strike price and time to maturity.
Portfolio A: one European call option plus a zero-coupon bond that provides a payoﬀ of K at time T
Portfolio C: one European put option plus one share of the stock.
We continue to assume that the stock pays no dividends. The call and put options have the same strike price K and the same time to maturity T.