WHAT IS THE RATIONALE BEHIND THE CONSTRUCTION OF THE INDEX?
The low-volatility strategy has gained in popularity over the past few years. This is mostly due to the “low-volatility anomaly” phenomenon, which suggests that lowervolatility stocks have historically outperformed higher-volatility stocks on a risk-adjusted basis over medium- to longterm periods.
For investors who are interested in harvesting the low-volatility anomaly but aren’t willing to lower their risk-based equity exposure, it may make sense to use leverage on top of a low-volatility portfolio. Such a strategy has long been implemented by institutional investors, including, to a certain extent, Warren Buffet.
This is the rationale behind the construction of the S&P 500 Low Volatility Target Beta Index. This new index is essentially the S&P 500 Low Volatility Index leveraged to a beta. The leverage level is set to be inversely proportional to the 252-day beta of the S&P 500 Low Volatility Index with respect to the S&P 500 at each rebalancing. The funding cost is based on the one-month U.S. dollar LIBOR rate.
HOW DOES THE INDEX WORK?
Historically, the S&P 500 Low Volatility Target Beta Index has outperformed the S&P 500 in terms of absolute and risk adjusted returns for three reasons. First, it takes advantage of the “low-volatility anomaly.” Second, it provides leverage by using the target beta overlay effectively. Third, it benefits from the correlation skew— the fact that the correlation between the stocks increases during a market crash.
The “correlation skew” is a robust statistical phenomenon in equity markets. When the market panics (like at the end of 2008), the correlation within the stock market tends to increase, which reduces the leverage within the S&P 500 Low Volatility Target Beta Index. This deleveraging effect adds an additional cushion on the downside.
