Cap/Floor
Table of Contents
A cap, floor, or collar bounds the floating coupons of an interest
rate leg. The product is a series of European options on the rate
fixings. ORE models it with the trade type CapFloor. 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 | Cap/Floor |
| Short name | Cap/Floor |
| ORE Studio product code | CapFloor |
| Asset class | rates |
| Family | Option |
| ORE trade data node | CapFloorData |
| ORE documentation | capfloor.tex |
2. Summary
A single floating swap leg benchmarked to IBOR or CMS indices may carry a cap, a floor, or a collar. The cap or floor rate is the strike. Each floating rate reset date is an option expiry date. The result is a series of European caplets or floorlets. A collar is the combination of a long cap and a short floor for a long position. Standalone caps and floors with a single payoff are also supported.
3. Detail
3.1. What it is
ORE defines the product as follows:
A single floating swap leg with interest payments benchmarked to IBOR or CMS indices, may have a cap, floor, or collar. This creates a series of European interest rate options (caplets or floorlets) where the cap or floor rate is the strike price, and each floating rate reset date is an option expiry date.
Source: ORE User Guide, Products catalogue, capfloor.tex.
ORE states the collar composition as follows:
A collar is the combination of a series of long caplets and short floorlets for a long position in the collar.
Source: ORE User Guide, Products catalogue, capfloor.tex.
ORE also supports the standalone form:
Standalone caps and floors with a single payoff on an IBOR or CMS index are also supported.
Source: ORE User Guide, Products catalogue, capfloor.tex.
3.2. In plain terms
A floating coupon pays whatever the index fixes. A cap sets a ceiling on that payment. A floor sets a floor beneath it. A collar does both. The option buyer pays a premium. If the fixing is above the cap rate, the caplet pays the difference. If the fixing is below the floor rate, the floorlet pays the difference.
3.3. How it works in ORE
The CapFloorData node is the trade data container for the
CapFloor trade type. It carries a LongShort sub-node for the
position. One LegData sub-node sets the leg type. The type can be
Floating for IBOR and OIS indices, CMS, CMSSpread,
DurationAdjustedCMS, CPI, or YY. The Caps or Floors
elements, or both, sit outside the leg node. With both, the
instrument is a collar and Caps must come above Floors. ORE notes
that the Payer flag is ignored for this instrument. The optional
PaymentDates node in the leg serves only OIS and IBOR indices.
3.4. Mathematical notes
ORE states the caplet payoff on an IBOR floating leg coupon period as follows:
Caplet payoff = N x max(0, L - K) x δ
N is the notional. L is the IBOR index fixing for the period. K is the cap rate, the strike. δ is the day-count fraction for the coupon period. The floorlet payoff is the mirror image:
Floorlet payoff = N x max(0, K - L) x δ
For a caplet or floorlet on a CMS index, L is replaced by the CMS rate of the relevant tenor. The standalone form pays:
Payoff = N x max(0, ω x (L - K))
ω is 1 for a cap and -1 for a floor.
3.5. What moves its value (static sensitivities)
- The level of the reference index against the strike.
- The cap or floor rate itself.
- The volatility of the index fixings.
- The reset frequency and the day-count convention.
- The discount curve.
The cap pays when the fixing exceeds the strike. The floor pays when the fixing falls below it. Near the strike, each caplet or floorlet shows its strongest gamma and vega.
3.6. How the profile ages (dynamic sensitivities)
Caplets and floorlets settle one per period. Each reset date is the expiry date of that period's option. Once a fixing settles, that option is decided and gone. The remaining value is the strip of options not yet decided. As each period passes, the number of live options falls by one.
3.7. Why a customer would want it
A borrower with floating debt buys a cap to bound the funding cost. An investor holding floating notes buys a floor to protect income. A collar sells one side to pay for the other. In ORE Studio a customer books caps and floors to value them and run sensitivities on the ORE engine.
3.8. Example
ORE's catalogue shows a long cap on a floating leg with a 5 percent cap rate and an upfront premium:
<CapFloorData> <LongShort>Long</LongShort> <LegData> <Payer>false</Payer> <LegType>Floating</LegType> ... </LegData> <Caps> <Cap>0.05</Cap> </Caps> <Premiums> <Premium> <Amount>1000</Amount> <Currency>EUR</Currency> <PayDate>2021-01-27</PayDate> </Premium> </Premiums> </CapFloorData>
Source: ORE User Guide, Products catalogue, capfloor.tex,
listing Cap/Floor data.
4. See also
- Knowledge — the hub of all knowledge notes, with the alphabetical product run.
- Wikipedia: Interest rate cap and floor. This note follows its general definition.
- ORE User Guide, Product catalogue: products.tex, which inputs capfloor.tex. The upstream project is OpenSourceRisk/Engine.