SDX Interest Rates Help > Supported Instruments > YoY Inflation Floor

YoY Inflation Floor

A year-over-year inflation floor protects its buyer from a fall in the year-over-year inflation below the level (i.e., the strike) specified in the contract.

It consists of a series of floorlets. Each floorlet successively ensures the buyer protection against a fall in the year-over-year inflation rate below the strike for a single payment period. That is, if on the floorlet’s payment date (usually at the end of the floorlet period) its year-over-year inflation rate is below the strike, the floor seller must pay the buyer a payoff as follows:

(Strike - year-over-year inflation change) * notional * relevant daycount fraction

Where:

The year-over-year inflation change is calculated as follows:

End index / ref index

The end index is the inflation index expected on the floorlet's end date.

The ref index is the inflation index measured on the date a year prior to the floorlet's end date. So, for example, if the floorlet’s end date is set to 10 October 2012, the reference index is displayed for 10 October 2011.

 

This can also be for a date in the future.

Advantages of a YoY inflation floor

Buying a YoY inflation floor lets you hedge yourself against falling YoY inflation rates for a specified period, while giving you the flexibility to benefit from any rise in rates.

Pricing a YoY inflation floor

When pricing a YoY inflation floor in the system:

You can price an inflation floor on any of the following currencies, each of which has one or more standard inflation indexes:

GBP which is based on UKRPI. This is the CPI for All Urban Customers (also known as CPI-U).

USD which is based on USCPI.

EUR which can be based on either HICPxT or FRCPI.

Note that each index rolls according to its own convention. For more information, see Understanding the Inflation Index Conventions .

For the strike you can define an absolute strike or enter “a” to indicate the ATM forward strike.

By default, the system sets each floorlet’s payment on the relevant floorlet’s end date. You can change these dates manually. However, the payment date cannot be prior to the end date.

In the Cash Flow Dates window, the implied rate is the expected% change in the year-over-year inflation rate.

The system:

Needs to know which forward index interpolation method to use.

For more information, See "Selecting the Forward Index Interpolation Method for Inflation Instruments".

Needs to know to deal with seasonality.

For more information, See "Customizing the Seasonality Adjustment for Inflation Instruments".

Needs to know from when to calculate the seasonality.

For more information, see Defining Which Reference Index to Use to Calculate the Seasonality

The system uses inflation rates which are taken by lag definition, even if more recently published rates are available.

When you define the instrument’s tenor, the system automatically displays the default inflation lag for the selected index in the Inflation Lag field. However, you can then edit this value if required. This lets you instruct the system to price the instrument using a non-default inflation lag.

 

If you are using seasonality and you have also instructed the system to measure the seasonality using the newest index available, the system does not use the inflation lag for the seasonality calculation, even if you have manually defined the inflation lag in the pricing page itself (in the Inflation Lag field).