Does interest start to accrue on purchase date or settlement date for bonds?

Answer 1

You are correct that the calculation of interest payments on bonds, asset-backed securities (ABS), mortgage-backed securities (MBS), and fixed-income securities often follows a settlement date approach. The settlement date approach is a common method used in financial markets to determine when interest payments are made to bondholders and investors. Here's how it works:

Settlement Date: The settlement date is the date on which a financial transaction is completed, and ownership of the security is transferred from the seller to the buyer. It's also the date on which the purchase price is paid, and the security is delivered to the buyer.

Accrued Interest: When a bond or fixed-income security is bought or sold between interest payment dates (coupon dates), the buyer typically pays the seller the accrued interest. Accrued interest is the interest that has accrued on the security since the last coupon payment date.

Regular Coupon Payments: The issuer of the bond or security makes regular coupon payments to the bondholders on specified dates, typically semiannually or annually. These coupon payments are based on the nominal or face value of the security and the coupon rate.

Adjustment at Settlement: When a security is bought or sold, the accrued interest is adjusted at the settlement date. The buyer compensates the seller for the accrued interest that has accumulated up to that point.

Next Coupon Payment: After the settlement date, the new owner of the security is entitled to receive the next scheduled coupon payment in full, as they have compensated the seller for the accrued interest.

The settlement date approach ensures that the buyer receives the full coupon payment for the period they hold the security, while the seller is compensated for the interest that accrued during their ownership.

This approach is especially important in fixed-income markets because it provides a fair way to account for the interest payments between coupon dates, ensuring that both the buyer and seller receive their respective portions of the interest income based on their ownership periods. It also allows for a clear delineation of responsibilities regarding interest payments and accruals when securities change hands.

It's worth noting that in some cases, the interest calculation method may vary depending on the specific terms and conventions outlined in the bond or security's prospectus or offering documents. Therefore, it's essential to refer to the specific terms of the security in question to understand how interest payments are calculated and when they are made.

Answer 2

For the purposes of calculating interest income after one has purchased a bond, interest begins to accrue on the settlement date of the purchase (not the trade date.) Unlike stocks, the ownership of which begins on trade date, ownership of a bond begins on settlement date. Therefore, settlement date can be thought of as the purchase date. In order to calculate "accrued interest", or interest payable to the seller, at the time of purchase, the accrual period begins on the date of the last interest payment or the original issue date if the first interest payment has not yet occurred. Accriued interest is calculated through the day immediately preceding the settlement date.