Zero Coupon Swap
Table of Contents
A zero coupon swap postpones the coupons of one leg into a single
payment at maturity. That leg behaves like a zero-coupon bond. ORE
models the product as a Swap with one leg of type
ZeroCouponFixed. This note records the domain grounding, as ORE
documents it in its product catalogue.
1. Identifiers
What a trader books it as, and what to grep for. The codes are the trade type catalogue's, which is what the database enforces.
| Field | Value |
|---|---|
| Full name | Zero Coupon Swap |
| Short name | Zero Coupon Swap |
| ORE Studio product code | none; not a product in its own right |
| Asset class | rates |
| Family | Swap |
| ORE trade data node | ZeroCouponFixedLegData on a Swap |
| ORE documentation | zerocouponswap.tex |
2. Summary
A zero coupon swap has at least one zero-coupon leg. The leg makes no
interest coupon payments during the life of the swap. It makes one
final interest payment at maturity, akin to a zero-coupon bond. The
zero-coupon leg compounds at the tenor of the swap. ORE sets the
product up as a swap with a ZeroCouponFixed leg.
3. Detail
3.1. What it is
ORE defines the product as follows:
A Zero-Coupon Swap has at least one zero-coupon leg. This leg has no interest rate coupon payments during the life of the swap, just one final interest payment at maturity, akin to a zero-coupon bond. The zero-coupon leg compounds at the tenor of the swap.
Source: ORE User Guide, Products catalogue, zerocouponswap.tex.
ORE sets the product up as a swap, trade type Swap, with one leg of
type ZeroCouponFixed. The ZeroCouponFixed leg carries an
additional ZeroCouponFixedLegData block. The block holds the rates
and the compounding convention of the leg.
3.2. In plain terms
Swap legs usually exchange coupon streams at regular dates. A zero-coupon leg changes that rhythm. It pays nothing during its life. One final payment then settles the interest that has accrued. The leg suits a party that wants a single bullet payment at a known date.
3.3. How it works in ORE
The product data uses the SwapData container of the Swap trade
type. One LegData node describes the floating leg. The other
LegData node sets LegType to ZeroCouponFixed and embeds a
ZeroCouponFixedLegData block. The block lists the Rates and the
Compounding convention. ORE's example below pays floating and
receives zero-coupon fixed at 2 percent with simple compounding.
3.4. Mathematical notes
The zero-coupon leg compounds at the tenor of the swap. It behaves
like a zero-coupon bond written on the leg notional. The final
payment depends on the fixed rate, the notional, the tenor, and the
compounding convention. Simple compounding accrues one payment over
the full life of the leg. The floating leg accrues and pays coupons
in the usual way.
3.5. What moves its value (static sensitivities)
- The discount curve and the swap rates across maturities.
- The fixed rate and the compounding convention of the zero-coupon leg.
- The floating index fixings on the other leg.
- The notional and the day-count convention.
- The distance to the single payment date.
The trade concentrates most interest-rate risk in the one final payment. Its value therefore loads on the discount factor to that maturity.
3.6. How the profile ages (dynamic sensitivities)
The zero-coupon leg accrues steadily toward its final payment. The present value of that payment grows as maturity approaches. The discount sensitivity of the payment shrinks as the payment date gets nearer. The floating leg keeps resetting with the market until maturity. At maturity the final payment settles and the trade stops.
3.7. Why a customer would want it
A customer with a bullet liability can match it with a zero-coupon leg. A zero-coupon bond issuer can hedge the redemption payment. The structure removes the reinvestment decisions that coupon streams bring. In ORE Studio a customer books zero coupon swaps to value them and run sensitivities on the ORE engine.
3.8. Example
ORE's catalogue shows a swap with a floating leg and a zero-coupon fixed leg:
<SwapData> <LegData> <LegType>Floating</LegType> <Payer>true</Payer> ... </LegData> <LegData> <LegType>ZeroCouponFixed</LegType> <Payer>false</Payer> ... <ZeroCouponFixedLegData> <Rates> <Rate>0.02</Rate> </Rates> <Compounding>Simple</Compounding> </ZeroCouponFixedLegData> </LegData> </SwapData>
Source: ORE User Guide, Products catalogue, zerocouponswap.tex,
listing Zero Coupon Swap Data.
The plain vanilla swap family sits in the Swap note. The zero coupon swap is that product with a deferred payment leg.
4. See also
- Knowledge — the hub of all knowledge notes, with the alphabetical product run.
- Wikipedia: Zero-coupon bond. The zero-coupon leg behaves like this instrument.
- Wikipedia: Interest rate swap. This note follows its general definition.
- ORE User Guide, Product catalogue: products.tex, which inputs zerocouponswap.tex. The upstream project is OpenSourceRisk/Engine.