Skip to content
All library documents

Pricing Swaps for Unhedgeable Cashflow Variability

Article Quant Q&A · Author: blah_crusader

Summary

The document considers an OTC swap intended to offset deviations of stochastic contract cashflows from their expected values. It frames the central pricing question as determining the premium for taking on that residual variability, which may arise from client behavior such as early termination. Mortgage prepayments are offered as an example of a similar risk that may lack a direct financial hedge.

The response treats the exposure as unhedgeable risk and suggests using the cashflow’s standard deviation as a first-order measure of its riskiness. A premium could be set as a multiple of that measure, with the multiplier reflecting risk aversion. This is a conceptual proposal rather than a complete valuation method: it does not specify the multiplier, discounting, aggregation across time, or a calibration procedure. Simulation is available in the setup, but the answer does not show how to use it to derive a premium.

Key ideas

  • The proposed swap transfers deviations of realized cashflows from their expected values.
  • Client actions such as early termination can create cashflow variability that is difficult to hedge.
  • Standard deviation is suggested as a first-order measure of the residual risk.
  • The premium may be modeled as a risk-aversion factor times that risk measure.
  • The proposal does not specify how to calibrate the factor or value cashflows over time.

Tags

Full text
# How to price OTC swaps to hedge non-economic cashflow variability


# How to price OTC swaps to hedge non-economic cashflow variability












Suppose we have a stochastic cashflow $X_t$ from a portfolio of contracts with clients. We can simulate from $X_t$ and can calculate $E[X_t], \forall t \in [1,n]$ where $n$ represents the longest maturity of all contracts in the portfolio. The cashflow variability arises from the unexpected behavior of clients since clients have embedded options in the contract to quit the contract early et cetera. Suppose we would like to hedge the variability of such cashflows using a swap contract. We might enter into an OTC swap contract if we find a counterparty that takes on the deviation of the cashflow with the expected cashflow, let's say one leg paying $X_t-E[X_t]$ and the other leg pays $E[X_t] + \pi$, where $\pi$ is the premium paid for the contract. How would one price such a contract, i.e. determine $\pi$ ? Note that we can assume we can simulate from $X_t$.

## Answer by dm63 (score 1)

https://quant.stackexchange.com/a/69219

One example of this situation might be pricing mortgages where we know the expected prepayment rate, but it could vary either to the high side or the low side, and there is no way to hedge the residual risk using other financial instruments. Essentially we are asking how to price unhedgable risk, so I would think that you have to look at the riskiness of the flow, as measured to first order by the standard deviation $E[(X_t-E[X_t])^2]$, Denoting this by $\sigma$, one could propose that $\pi=k\sigma$ for some value of $k$, where $k$ is a measure of risk aversion.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.