Turbulence Can Improve Portfolio Diversification

"The only problem with diversification is that it's never been tried," said Mark Kritzman, president and CEO of Windham Capital Management, in a July 21 speech to the Boston chapter of the Quantitative Work Alliance for Applied Finance, Education and Wisdom (QWAFAFEW). If he gets his way, investors will apply his concept of turbulence to achieve truly diversified portfolios.  Advisor Perspectives interviewed Kritzman after his QWAFAFEW talk to get details on how financial advisors can benefit from turbulence.

Classic diversification has failed, Kritzman said, because traditional, independent measures of volatility and correlation don’t provide enough information to indicate which portfolios will deliver the lower risk or higher returns that, at least theoretically, should come with investing in imperfectly correlated asset classes. To see the failure of classically diversified portfolios, one need not look any farther than the recent financial crisis, when correlations converged toward one and “diversified” portfolios plummeted.

Turbulence vs. VIX

“Turbulence is a measure of statistical unusualness that takes into account both the magnitude of returns and how they interact with one another,” said Kritzman. “A period is deemed turbulent if either the returns are different in magnitude from their norm or if the assets interact in an uncharacteristic way.”

In other words, turbulence is a statistical measure of both volatility and correlation. It differs from narrower metrics such as the VIX index, which measure only one asset class (the S&P 500 in the case of the VIX) and don’t take into account correlations across asset classes.

Volatility alone doesn’t capture enough information about interactions between assets, Kritzman said. Consider two portfolios with the same volatility. The first portfolio’s components could have high standard deviation and low correlations, while the second could have low standard deviation and high correlations. The investor who only considers volatility lacks important information about whether correlations are acting typically or not. “It’s like living in Boston and having just one set of clothes for the average temperature,” Kritzman said.

By incorporating information about correlations, turbulence indicates—in a way that volatility cannot—whether markets are decoupling or converging. This is important because when assets act uncharacteristically, hedging and other investment strategies that rely on consistent correlations may not work.

Measures such as VIX have additional shortcomings, according to Kritzman. They are only available for asset classes that have liquid option markets, and they are forward-looking measures, so they don’t measure what’s actually going on now.