Serial bonds are a type of bond issuance in which the bonds are scheduled to mature in a series of installments over a period of time rather than all at once upon a single maturity date. This structure allows the issuer, typically a government or corporation, to manage its debt repayment more gradually and efficiently.

Here's how serial bonds work:

1. Multiple Maturities: Unlike traditional bonds with a single maturity date, serial bonds have multiple maturity dates spread out over several years. Each bond in the series matures on a specific predetermined date.

2. Staggered Repayment: The staggered maturity dates mean that the issuer doesn't have to repay the entire principal amount of the bonds in a lump sum when they become due. Instead, the issuer repays a portion of the principal at each maturity date, reducing the overall debt burden over time.

3. Matching Revenue Streams: Serial bonds are often used by entities that expect their revenue streams to increase gradually over time. For example, a local government funding a public infrastructure project might issue serial bonds that mature as tax revenues rise.

4. Interest Payments: Interest payments are made on each bond in the series until its maturity date. The interest rate is typically fixed at the time of issuance, but it may vary for different bonds within the series, especially if the issuer's creditworthiness changes over the term.

5. Investor Appeal: Serial bonds can appeal to investors looking for a predictable and regular stream of income from their bond investments since these bonds mature periodically, providing opportunities for reinvestment.

Serial bonds offer a structured approach to managing debt, enabling issuers to match their repayment schedule with their projected cash flows. This type of bond issuance can be beneficial for both the issuer and investors seeking a combination of regular income and predictable repayment of principal.