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Reducing Heston Pricing Oscillations with Fourier Methods

Article Quant Q&A · Author: Sam Palmer

Summary

The document addresses unstable numerical integration in Heston option pricing, where an oscillatory or slowly decaying integrand can produce negative computed prices, especially for deep out-of-the-money options. A recommended first remedy is the Little Trap formulation, which improves the characteristic-function representation. The responses also favor Fourier-based pricing methods over straightforward integration in difficult parameter regions.

Suggested techniques include choosing a stable characteristic-function form, shifting the integration contour, and subtracting a Black–Scholes price as a control variate to smooth the integrand. Other approaches include FFT or fractional FFT, an optimized contour, adaptive Filon quadrature, and Fourier-cosine expansions. These are numerical remedies rather than guarantees: the best method depends on parameter values and implementation, and the discussion does not provide benchmark comparisons or specific accuracy settings.

Key ideas

  • Heston pricing integrands can oscillate or decay slowly, causing numerical errors such as negative computed prices.
  • The Little Trap formulation is one proposed way to improve the characteristic-function calculation.
  • Contour shifts and stable characteristic-function forms can improve Fourier integration behavior.
  • A Black–Scholes control variate can smooth the integrand and remove problematic components.
  • FFT, adaptive Filon quadrature, and Fourier-cosine expansions are alternative numerical approaches.

Tags

Full text
# Heston Model Integration Oscillations


# Heston Model Integration Oscillations












Is there a way to reduce oscillations for the numerical integration when evaluating the Heston model. I am pricing a series of 5000 options scattered over the Heston model parameter space and I find that for some parameters, often deep-out-of-the-money options I get negative option prices. I am using 32 Gauss-Laguerre integration, so the integration grid is rather fine, also I have tried extending the maturities to say 10 years, but this only reduces the frequency.

If not I guess Monte-Carlo is the only way to make sure I get no negative prices.

Thanks Sam

## Answer by user16651 (score 5, accepted)

https://quant.stackexchange.com/a/28063

> In SV model, it is well-known that the integrand for the call price can sometimes show high oscillation, can dampen very slowly along the integration axis, and can show discontinuities.

Remedy

- The ‘‘Little Trap’’ formulation of Albrecher et al.

Also , you can use Fourier transforms

- Bakshi and Madan (2000)

- Lewis,(2001).

- Gatheral (2006)

- Carr and Madan (1999)

## Answer by Mark Joshi (score 7)

https://quant.stackexchange.com/a/28068

There has been a huge amount of work on this. Generally a Fourier transform approach is used.

First, be careful to use the form of the characteristic function that does not wind about zero in order to avoid having to count the normal of windings.

Second, using contour shifts can make the integral much better behaved. eg integrate along the line with $0.5$ imaginary part to price a covered call.

Third, use a Black--Scholes call with the same strike as a control. This removes poles and makes the integrand much nicer.

For details, see my book More Mathematical Finance Chapter 17 and/or my paper http://ssrn.com/abstract=1941464 Fourier Transforms, Option pricing and controls.

## Answer by Kiwiakos (score 4)

https://quant.stackexchange.com/a/28067

I'd use FFT or similar rather than direct integration. Here is an old paper with Heston example:

Option pricing using fractional FFT

## Answer by jherek (score 2)

https://quant.stackexchange.com/a/44708

This is a well known issue. There are three possible tricks:

- I am surprised that none of the answers so far mention the work of Lord and Kahl Optimal Fourier Inversion in Semi-Analytical Option Pricing. They study this oscillation problem and propose an optimal contour for the integration. The challenge is to write a small algorithm to obtain the optimal $\alpha$. I believe it can be found in an article from Mike Staunton in a recent Wilmott magazine issue.

- A different trick is to use the Black-Scholes model as control variate in the integration (its characteristic function). This is detailed in Andersen and Piterbarg book "Interest Rate Modeling, Volume I: Foundations and Vanilla Models", as well as in @MarkJoshi and Chan paper.

- Use a quadrature that takes care of oscillations naturally. This is the approach described in An adaptive Filon quadrature for stochastic volatility models.

## Answer by James Spencer-Lavan (score 2)

https://quant.stackexchange.com/a/44723

Use Fourier-Cosine expansions and you will never look back. Very easy to programme, maths is more intuitive also. Fang & Oosterlee, 2008 (edit: corrected the name)

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.