An option contract that may only be exercised on the expiration date. For example, if one buy a European call giving him/her the right to buy shares in X expiring on the final Friday in March, the call may only be exercised on the final Friday in March. The implication of a European option is the fact that its value is entirely dependent on the value of the underlying asset at the end of the contract. A holder may not wait for an advantageous price and exercise the option. This contrasts with an American option, which may be exercised at any time prior to expiry.