Classifying ETFs
A key tenet of asset allocation is diversification across asset classes and subclasses having discernable differences in return and risk characteristics. Classification of equities according to style and sector characteristics (as well as capitalization and geographic coverage) enables index investors to “fence off” exposure and risk based on the composition of holdings.
Style attribution classifies a stock as “growth” or “value”. Growth stocks tend to have relatively high price-to-earnings (P/E) ratios and rapid earnings growth. Value stocks tend to have relatively low P/Es and price-to-book (P/B) ratios. Most style-based indexes, such as those of S&P and Russell, rely heavily on the inverse of P/B (i.e., B/P) to classify stocks as either growth or value.
Style, capitalization and geographic coverage are frequently used in combination. Exposure to U.S. all-cap growth stocks, for example, can be gained by using iShares Russell 3000 Growth ETF (IWZ) whereas exposure to U.S. small-cap value stocks can be gained via iShares S&P/Barra Small Cap 600 Value (IJS).
These classification “gradients” enable the disciplined investor to maintain tight control over exposure to assets having, by design, diversified performance and risk attributes.
Over-weighting, underweighting, eliminating or even taking on inverse exposure, whether for hedging purposes or otherwise, can be done with surgical precision via style and sector-based ETFs.
Of the industry’s 751 ETFs as of July 31, according to StateStreet, 90 were style and capitalization-based equity ETFs, holding $232 billion, and 115 sector-based equity ETFs valued at $59 billion. Industry totals stood at 751 ETFs holding $640 billion in assets.