> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fincept.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Models and calibration

> Heston, Bates, piecewise time-dependent Heston and GJR-GARCH calibrated to option volatilities; Hull-White, Black-Karasinski, G2++, Vasicek, CIR, extended CIR and GSR calibrated to swaption and cap volatilities; zero-coupon bond prices, bond options and short-rate statistics under a short-rate model.

Toolset `pricing_models`: 3 tools.

| Tool | What it does | Notes |
| - | - | - |
| `pricing_heston_calibration` | Calibrates a Heston (or Bates, piecewise time-dependent Heston, GJR-GARCH) model to implied-volatility quotes by expiry and strike with a chosen optimiser, optionally holding some parameters fixed. | |
| `pricing_short_rate_calibration` | Calibrates a short-rate model (Hull-White, Black-Karasinski, G2++, Vasicek, CIR, extended CIR, or GSR step volatilities) to ATM swaption and cap volatilities (normal or lognormal) on the curve, with a chosen optimiser and optionally fixed parameters. | |
| `pricing_short_rate_model` | Analytics of a short-rate model with given parameters: model discount factors and zero yields at maturities (the curve for fitted models, the model's own curve for Vasicek and CIR), European options on zero-coupon bonds, the Hull-White futures convexity bias, and the mean and standard deviation of the short rate over time for Hull-White. | |

Inputs, limits and outputs are described in [Fincept Pricing](/guides/fincept-pricing). Full schemas: `fincept_describe_tool`.


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.