: This fundamental theorem establishes an exact theoretical linkage between the price of a European call option, its corresponding put option, the underlying asset price, and the present value of the strike price. Maintaining this equality is a cornerstone of options pricing theory across all asset classes. Any violation signals an immediate opportunity for risk-free profit.
Principle
: The concept dictates that a portfolio consisting of a long call and a short put, both with identical strike and expiry, must equal a portfolio of a long underlying asset and a short risk-free bond. Traders use this principle to construct synthetic positions or to validate the consistency of quoted prices. Adherence to this relationship is a necessary condition for market efficiency.
Arbitrage
: Detecting a breach of this parity allows for the construction of a self-financing trade that guarantees a positive return irrespective of the final asset price. Such opportunities are rare in mature markets but can occasionally surface in less liquid crypto options markets. Rapid execution is required to capture the profit before automated systems correct the imbalance.
