Risk Parity Portfolio Model

The model's inputs are asset class expected returns, volatilities, and correlations, along with leverage parameters, fee rates, financing rates, rebalancing assumptions, and the projection period. These drivers determine the risk-parity weights, which are derived from inverse volatility rather than fixed assumptions.

• The leverage ratio, typically between 1.5x and 3.0x of NAV, scales the portfolio's exposures and amplifies both returns and volatility. Financing costs are applied only to the borrowed portion, calculated as (Leverage Ratio - 1) times NAV times the financing rate, and represent the dominant cost drag.
• Transaction costs apply to the rebalanced portion, so turnover assumptions matter, and a cash buffer of 2-5% is held for margin calls and rebalancing. The model uses consistent base rates for financing and the risk-free rate to avoid overstating net returns.

The model computes inverse-volatility weights so that each asset class contributes equally to portfolio variance. Capital weights are these inverse-volatility weights before leverage.

• Leveraged exposure per asset is capital weight times leverage ratio times total NAV. The portfolio gross return is the weighted sum of expected returns multiplied by the leverage ratio.
• Financing cost is subtracted, as are management fees and transaction costs, to arrive at net return. The risk contribution of each asset is its capital weight times its volatility divided by portfolio volatility; in a correctly specified risk-parity portfolio, these contributions are approximately equal.

Portfolio volatility uses the full covariance matrix, incorporating correlations, rather than a simple weighted sum of volatilities. The Sharpe ratio compares net return minus the risk-free rate to portfolio volatility, and the NAV roll-forward compounds net returns to project ending portfolio value.

The model produces a set of risk and return metrics: portfolio volatility, Sharpe ratio, an estimated maximum drawdown based on a 99% VaR proxy, and Value-at-Risk. Critically, it includes a risk contribution verification to confirm that each asset class contributes equally to total risk; if they do not, the weights are incorrectly specified.

• The AUM roll-forward reconciles beginning NAV, returns, fees, financing costs, and distributions to ending NAV. Additional checks ensure that capital weights sum to 100%, that leveraged portfolio volatility equals unleveraged volatility times the leverage ratio, and that total fees as a percentage of NAV fall within a sensible range.
• These checks help identify common errors such as forgetting to leverage volatility alongside returns or using a volatility formula that ignores correlations.

This model is intended for portfolio managers, CIOs, family offices, and institutional allocators assessing whether a risk-parity approach fits their objectives and constraints. By varying assumptions for expected returns, volatilities, correlations, and leverage, users can see how target return and risk interact.

• The model flags when implied leverage exceeds a maximum allowed, which is important because a decline in portfolio value can raise effective leverage and trigger forced deleveraging. It also highlights the impact of financing costs on net returns and the role of rebalancing frequency through transaction costs.
• The output helps answer whether the required leverage to hit a return target is prudent given margin maintenance requirements and the investor's risk tolerance.