toraniko-model

Factor return estimation for the toraniko factor model.

Overview

This crate provides the core factor return estimation logic, implementing a characteristic factor model similar to Barra and Axioma systems.

Key Types

• FactorReturnsEstimator - Main entry point for factor return estimation
• EstimatorConfig - Configuration for the estimator

Usage

use toraniko_model::{FactorReturnsEstimator, EstimatorConfig};
use toraniko_traits::ReturnsEstimator;

let estimator = FactorReturnsEstimator::with_config(EstimatorConfig {
    winsor_factor: Some(0.05),
    residualize_styles: true,
});

let (factor_returns, residuals) = estimator.estimate(
    returns_df,
    mkt_cap_df,
    sector_df,
    style_df,
)?;

Mathematical Model

The factor model decomposes asset returns as:

r_asset = β_market * r_market + Σ(β_sector * r_sector) + Σ(β_style * r_style) + ε

Where:

• r_market is the market factor return
• r_sector are sector factor returns (constrained to sum to zero)
• r_style are style factor returns
• ε is the idiosyncratic residual