Risk Parity

Risk parity was popularized by Bridgewater Associates, whose All Weather Fund is one of the most prominent examples of the strategy in practice. The central insight behind risk parity is that traditional 60/40 portfolios (60% equities, 40% bonds) are not balanced from a risk perspective — equities typically contribute 90% or more of the total portfolio's volatility because stocks are far more volatile than bonds. A 60/40 portfolio is therefore economically equivalent to a portfolio that is nearly 100% in equity risk.

Risk parity addresses this imbalance by measuring each asset class's volatility and correlation with other holdings, then allocating capital inversely to volatility so that each asset contributes equally to the total portfolio risk budget. In practice, this means holding substantially less in equities and substantially more in fixed income and other lower-volatility assets. To achieve returns comparable to an equity-heavy portfolio, risk parity strategies frequently employ leverage on the fixed-income portion.

The appeal of risk parity is its diversification across economic environments rather than just asset classes. Bridgewater's framework identifies four economic environments defined by whether growth and inflation are rising or falling, then seeks to hold assets that perform well in each quadrant. Nominal bonds perform well in environments of falling growth and falling inflation. Equities outperform in rising growth. Inflation-linked bonds and commodities provide protection during periods of rising inflation.

Performance of risk parity strategies depends heavily on the interest rate environment. The extended bull market in bonds from the early 1980s through 2021 was highly favorable for risk parity because the leveraged fixed-income positions generated substantial returns. When interest rates rise sharply — as they did in 2022 — risk parity strategies can suffer significant drawdowns because leveraged bonds and equities frequently fall simultaneously, removing the diversification benefit the strategy depends on.

Implementation considerations include the cost of leverage (borrowing rates affect the return premium earned on leveraged low-yield assets), rebalancing frequency (risk weights shift as volatilities change and must be periodically rebalanced), and whether to use derivatives or physical securities for leverage. Risk parity is most accessible to institutional investors, though several mutual funds and ETFs now offer retail versions of the strategy.