On the date of issue of a security or investment contract, the yield refers to the coupon or interest on the security or contract. On any date after issuance, the yield of a security is based on the value of the security’s cash flows. Yield can be calculated in several ways. In general, the most common method is based on the income generated over a 12 month period divided by the net asset value generating the income. The yield of an investment contract is also known as the crediting rate.