https://github.com/donpushme/sv-model
https://github.com/donpushme/sv-model
Last synced: 10 months ago
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- Host: GitHub
- URL: https://github.com/donpushme/sv-model
- Owner: donpushme
- License: gpl-3.0
- Created: 2025-07-25T10:53:34.000Z (11 months ago)
- Default Branch: main
- Last Pushed: 2025-07-25T10:54:41.000Z (11 months ago)
- Last Synced: 2025-08-12T08:55:41.800Z (10 months ago)
- Language: Python
- Size: 10.2 MB
- Stars: 1
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE.txt
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README
# StochVolModels
Implementation of pricing analytics and Monte Carlo simulations for modeling of options and implied volatilities.
The StochVol package provides:
1) Analytics for Black-Scholes and Normal vols
2) Interfaces and implementation for stochastic volatility models,
including log-normal SV model and Heston SV model
using analytical method with Fourier transform and Monte Carlo simulations
3) Visualization of model implied volatilities
For the analytic implementation of stochastic volatility models, the package provides interfaces for a generic volatility model with the following features.
1) Interface for analytical pricing of vanilla options
using Fourier transform with closed-form solution for moment generating function
2) Interface for Monte-Carlo simulations of model dynamics
[Illustrations](#papers) of using package analytics for research
work is provided in top-level package ```my_papers```
which contains computations and visualisations for several papers
## Installation
Install using
```python
pip install stochvolmodels
```
Upgrade using
```python
pip install --upgrade stochvolmodels
```
Close using
```python
git clone https://github.com/ArturSepp/StochVolModels.git
```
Core dependencies:
python = ">=3.8",
numba = ">=0.56.4",
numpy = ">=1.22.4",
scipy = ">=1.10",
pandas = ">=2.2.0",
matplotlib = ">=3.2.2",
seaborn = ">=0.12.2"
Optional dependencies:
qis ">=2.1.38" (for running code in my_papers and volatility_book)
# Table of contents
1. [Model Interface](#introduction)
1. [Log-normal stochastic volatility model](#logsv)
2. [Heston stochastic volatility model](#hestonsv)
2. [Running log-normal SV pricer](#paragraph1)
1. [Computing model prices and vols](#subparagraph1)
2. [Running model calibration to sample Bitcoin options data](#subparagraph2)
3. [Comparison of model prices vs MC](#subparagraph3)
4. [Analysis and figures for the paper](#subparagraph4)
3. [Running Heston SV pricer](#heston)
4. [Supporting Illustrations for Public Papers](#papers)
Running model calibration to sample Bitcoin options data
## Implemented Stochastic Volatility models
The package provides interfaces for a generic volatility model with the following features.
1) Interface for analytical pricing of vanilla options using Fourier transform with closed-form solution for moment generating function
2) Interface for Monte-Carlo simulations of model dynamics
3) Interface for visualization of model implied volatilities
The model interface is in stochvolmodels/pricers/model_pricer.py
### Log-normal stochastic volatility model
The analytics for the log-normal stochastic volatility model is based on the paper
[Log-normal Stochastic Volatility Model with Quadratic Drift](https://www.worldscientific.com/doi/10.1142/S0219024924500031) by Artur Sepp and Parviz Rakhmonov
The dynamics of the log-normal stochastic volatility model:
$$dS_{t}=r(t)S_{t}dt+\sigma_{t}S_{t}dW^{(0)}_{t}$$
$$d\sigma_{t}=\left(\kappa_{1} + \kappa_{2}\sigma_{t} \right)(\theta - \sigma_{t})dt+ \beta \sigma_{t}dW^{(0)}_{t} + \varepsilon \sigma_{t} dW^{(1)}_{t}$$
$$dI_{t}=\sigma^{2}_{t}dt$$
where $r(t)$ is the deterministic risk-free rate; $W^{(0)}_{t}$ and $W^{(1)}_t$ are uncorrelated Brownian motions, $\beta\in\mathbb{R}$ is the volatility beta which measures the sensitivity of the volatility to changes in the spot price, and $\varepsilon>0$ is the volatility of residual volatility. We denote by $\vartheta^{2}$, $\vartheta^{2}=\beta^{2}+\varepsilon^{2}$, the total instantaneous variance of the volatility process.
Implementation of Lognormal SV model is contained in
```python
stochvolmodels/pricers/logsv_pricer.py
```
### Heston stochastic volatility model
The dynamics of Heston stochastic volatility model:
$$dS_{t}=r(t)S_{t}dt+\sqrt{V_{t}}S_{t}dW^{(S)}_{t}$$
$$dV_{t}=\kappa (\theta - V_{t})dt+ \vartheta \sqrt{V_{t}}dW^{(V)}_{t}$$
where $W^{(S)}$ and $W^{(V)}$ are correlated Brownian motions with correlation parameter $\rho$
Implementation of Heston SV model is contained in
```python
stochvolmodels/pricers/heston_pricer.py
```
## Running log-normal SV pricer
Basic features are implemented in
```python
examples/run_lognormal_sv_pricer.py
```
Imports:
```python
import stochvolmodels as sv
from stochvolmodels import LogSVPricer, LogSvParams, OptionChain
```
### Computing model prices and vols
```python
# instance of pricer
logsv_pricer = LogSVPricer()
# define model params
params = LogSvParams(sigma0=1.0, theta=1.0, kappa1=5.0, kappa2=5.0, beta=0.2, volvol=2.0)
# 1. compute ne price
model_price, vol = logsv_pricer.price_vanilla(params=params,
ttm=0.25,
forward=1.0,
strike=1.0,
optiontype='C')
print(f"price={model_price:0.4f}, implied vol={vol: 0.2%}")
# 2. prices for slices
model_prices, vols = logsv_pricer.price_slice(params=params,
ttm=0.25,
forward=1.0,
strikes=np.array([0.9, 1.0, 1.1]),
optiontypes=np.array(['P', 'C', 'C']))
print([f"{p:0.4f}, implied vol={v: 0.2%}" for p, v in zip(model_prices, vols)])
# 3. prices for option chain with uniform strikes
option_chain = OptionChain.get_uniform_chain(ttms=np.array([0.083, 0.25]),
ids=np.array(['1m', '3m']),
strikes=np.linspace(0.9, 1.1, 3))
model_prices, vols = logsv_pricer.compute_chain_prices_with_vols(option_chain=option_chain, params=params)
print(model_prices)
print(vols)
```
### Running model calibration to sample Bitcoin options data
```python
btc_option_chain = chains.get_btc_test_chain_data()
params0 = LogSvParams(sigma0=0.8, theta=1.0, kappa1=5.0, kappa2=None, beta=0.15, volvol=2.0)
btc_calibrated_params = logsv_pricer.calibrate_model_params_to_chain(option_chain=btc_option_chain,
params0=params0,
constraints_type=ConstraintsType.INVERSE_MARTINGALE)
print(btc_calibrated_params)
logsv_pricer.plot_model_ivols_vs_bid_ask(option_chain=btc_option_chain,
params=btc_calibrated_params)
```
### Comparison of model prices vs MC
```python
btc_option_chain = chains.get_btc_test_chain_data()
uniform_chain_data = OptionChain.to_uniform_strikes(obj=btc_option_chain, num_strikes=31)
btc_calibrated_params = LogSvParams(sigma0=0.8327, theta=1.0139, kappa1=4.8609, kappa2=4.7940, beta=0.1988, volvol=2.3694)
logsv_pricer.plot_comp_mma_inverse_options_with_mc(option_chain=uniform_chain_data,
params=btc_calibrated_params,
nb_path=400000)
```
### Analysis and figures for the paper
All figures shown in the paper can be reproduced using py scripts in
```python
examples/plots_for_paper
```
Examples are implemented here
```python
examples/run_heston_sv_pricer.py
examples/run_heston.py
```
Content of run_heston.py
```python
import numpy as np
import matplotlib.pyplot as plt
from stochvolmodels import HestonPricer, HestonParams, OptionChain
# define parameters for bootstrap
params_dict = {'rho=0.0': HestonParams(v0=0.2**2, theta=0.2**2, kappa=4.0, volvol=0.75, rho=0.0),
'rho=-0.4': HestonParams(v0=0.2**2, theta=0.2**2, kappa=4.0, volvol=0.75, rho=-0.4),
'rho=-0.8': HestonParams(v0=0.2**2, theta=0.2**2, kappa=4.0, volvol=0.75, rho=-0.8)}
# get uniform slice
option_chain = OptionChain.get_uniform_chain(ttms=np.array([0.25]), ids=np.array(['3m']), strikes=np.linspace(0.8, 1.15, 20))
option_slice = option_chain.get_slice(id='3m')
# run pricer
pricer = HestonPricer()
pricer.plot_model_slices_in_params(option_slice=option_slice, params_dict=params_dict)
plt.show()
```
## Supporting Illustrations for Public Papers
As illustrations of different analytics, this packadge includes module ```my_papers```
with codes for computations and visualisations featured in several papers
for
1) "Log-normal Stochastic Volatility Model with Quadratic Drift" by Artur Sepp
and Parviz Rakhmonov: https://www.worldscientific.com/doi/10.1142/S0219024924500031
```python
stochvolmodels/my_papers/logsv_model_wtih_quadratic_drift
```
2) "What is a robust stochastic volatility model" by Artur Sepp and Parviz Rakhmonov, SSRN:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4647027
```python
stochvolmodels/my_papers/volatility_models
```
3) "Valuation and Hedging of Cryptocurrency Inverse Options" by Artur Sepp
and Vladimir Lucic,
SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4606748
```python
stochvolmodels/my_papers/inverse_options
```
4) "Unified Approach for Hedging Impermanent Loss of Liquidity Provision" by
Artur Sepp, Alexander Lipton and Vladimir Lucic,
SSRN: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4887298
```python
stochvolmodels/my_papers/il_hedging
```
5) "Stochastic Volatility for Factor Heath-Jarrow-Morton Framework" by Artur Sepp and Parviz Rakhmonov, SSRN:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4646925
```python
stochvolmodels/my_papers/sv_for_factor_hjm
```