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04 / Systems / 2024–2025

Heston pricing and calibration.

Individual dissertation / Heston model

CONTRIBUTION

Individual dissertation · COM3610

BUILT WITH
PythonNumPy / CuPyPyTorchSciPy

01 / SCOPE

Problem and
scope.

Repeated option pricing can make model calibration expensive. My dissertation compared a NumPy CPU path, batched GPU evaluation and a learned surrogate to measure the trade-off between runtime and price-space error.

MY ROLE

I implemented the Heston pricing and calibration pipeline: NumPy Fourier–COS pricing, batched CuPy evaluation, bounded L-BFGS-B optimisation and a ten-feature PyTorch surrogate trained on 600,000 synthetic samples.

02 / IMPLEMENTATION

Implementation
details.

  1. 01Filter SPX contracts
  2. 02COS pricing
  3. 03Bounded optimisation
  4. 04Neural surrogate
  5. 05Compare trade-offs
01

Implement CPU and GPU pricing paths.

Implement Fourier–COS pricing with a NumPy CPU path, then evaluate batched pricing with CuPy.

02

Constrain the calibration parameters.

Use bounded L-BFGS-B optimisation to estimate the Heston parameters from filtered market contracts.

03

Train and evaluate an approximation.

Train a ten-feature PyTorch surrogate on a 600,000-sample synthetic design. Compare runtime and price-space error together rather than making speed the only objective.

03 / RESULTS

Results.

4.92 sCPU COS · RMSE 1.661350
2.52 sGPU COS · RMSE 1.661350
0.40 sNeural surrogate · RMSE 3.660689

One retained run used 93 filtered out-of-the-money SPX contracts from 2014-06-02. CPU and GPU COS reached the same retained RMSE; the neural surrogate was faster but less accurate. This run was not independently reproduced for the website.

Context & limitations

The reported experiment uses a single SPX market snapshot. Broader market-regime generalisation and repeated benchmark reproducibility remain limitations. Restricted market data and model artifacts are not redistributed here.

04 / SUMMARY

The surrogate reduced runtime in the retained run, but price error increased and the run was not independently reproduced.
NEXT PROJECT / 05

Speech modelling and detection.

Speech technology / VAD + GMM