Tuesday, March 28, 2017

Smart Beta: "They Can’t All Be That Smart"

Continuing our tour of some of the more interesting characteristics of the factor zoo.

From Investing Research, March 14:
Smart Beta is a label applied broadly to all factor-based investment strategies. In a recent WSJ article on Smart Beta, Yves Choueifaty, the CEO of Tobam, said “There’s a huge range of possibilities in the smart-beta world, and they can’t all be that smart.” This paper separates the factor investing landscape, gives a framework to analyze the edge of various approaches and lets you decide which factor-based strategy is worth your money.

Analysis of a factor-investing strategy should focus on two of the manager’s skills: the ability to identify specific factors that accurately generate out-performance and the manager’s technique in constructing a portfolio of stocks with those factors. Factors are not commodities, and one should know how managers are selecting stocks, but we are focusing on portfolio construction and the soundness of different approaches.

Active share can be a useful tool in this investigation. Active share by itself is not a metric that inherently identifies manager skill. Nor is it the best metric to determine the risk of the portfolio versus an active benchmark. Tracking error is a more comprehensive metric for the trailing differences in the portfolio returns and Information Ratios to understand the balance of how much active risk you are taking for active return. But active share is a very useful tool in investigating the choices managers make in building factor portfolios.

Through the lenses of active share, tracking error, and information ratios, we consider the relative merits of factor-based portfolio construction approaches: Fundamental Weighting, Smart Beta and Factor Alpha. Understanding the differences between these approaches will help you better incorporate factors into your overall portfolio.

Fundamental Weighting
Most benchmarks weigh constituents by market capitalization. Some factor investing approaches pivot away from weighting on market cap, and weighting on another fundamental factor like sales or earnings. The argument for these strategies is that weighting by market cap is not the smartest investment solution out there: the top quintile of the S&P 500 by market cap underperforms the average stock by -0.65% annualized1, and market cap weighting allocates 65% of the benchmark to those largest names.

For a comparison of fundamental weighting schemes, the table below shows the characteristics and annualized returns for weighting on Market Cap, Sales, Earnings, Book Value of Equity and Dividends. There are some benefits to the approach, for example eliminating companies with negative earnings. On average, about 8.3% of Large Stocks companies are generating negative earnings2, and avoiding those is smart. The largest benefit is an implied value-tilt to the strategy: over-weighting companies with strong earnings and average market caps creates an implicit Price/Earnings tilt. This is apparent in the characteristics table: Sales-weighting gives the cheapest on Price/Sales, Dividend-Weighted gives the highest yield, etc.

But pivoting from market cap to a fundamental factor weighting scheme does not create large risk-return benefits. Raw fundamental factors correlate highly with market cap; companies with huge revenues tend to have large market caps. As of December 31st, 2016, weighting on Earnings has a 0.85 correlation with weighting on market capitalization3. In market cap weighting, the top 25 names are 34% of the portfolio. In an earnings-weighted scheme those same 25 companies are still 34% of the portfolio, just shifting weights a bit from one name to another.

Active share shows how little fundamental weighting moves the portfolios, with active shares in the 20-30% range. Excess returns range from slightly underperforming market cap to outperforming by +72bps. The modest excess return comes with much higher active risk, and tracking errors ranging from 4.5% to 5.8%. This generates poor information ratios, the ratio of active return to active risk.

Portfolio Weight for Market Cap Weighted vs. Earnings Weighted – December 31st, 2016

Characteristics and Annualized Returns by Weighting Scheme (U.S. Large Stocks, 1963-2016)
The reason that the risk-return benefits are small is because Fundamental Weighting is an indirect allocation to a Value strategy. Value investing on ratios is identifying investment opportunities with the comparison of a fundamental factor in the context of the price you pay. Fundamental weighting is only taking half of the strategy into account, looking for large earnings but ignoring the price you’re paying for them. Some Fundamental Weighted products will be more sophisticated than simply weighting on sales, earnings, book value or dividends. But weighting on fundamental factors instead of market cap doesn’t create a significant edge.

Risk-Focused versus Return-Focused
A post by Cliff Asness at AQR suggested that Smart Beta portfolios should be minimizing active share. Smart Beta portfolios are “only about getting exposure to the desired factor or factors while taking as little other exposures as possible.” This statement cemented the idea that there is a group of Smart Beta products that are risk-focused in nature: Start with the market portfolio, identify your skill and then take only the exposure on those factors....MUCH MORE
Are Factor Investors Getting Paid to Take on Industry Risk?
Asness et al: "Contrarian Factor Timing is Deceptively Difficult"
"Investing: Cliff Asness Blasts Rob Arnott"   

And some older posts:
What a Long Strange Trip: From CAPM To Fama-French to Four (or more) Factor
Improving on the Four-factor (beta, size, value, momentum) Asset Pricing Model
2017 Credit Suisse Global Investment Returns Yearbook (and testing smart beta factors)
Factors: The Problem With Small Cap Stocks (the effect probably isn't real)
It's Anomalous: "Fact, Fiction and Momentum Investing"
Rob Arnott's Research Affiliates: "Finding Smart Beta in the Factor Zoo"