01-09-2016 · 研究

Factor investing versus sector investing

A recent study suggests that sector investing does as well or even better than factor investing in a long-only context. We challenge this conclusion and show that an explicit allocation to well established factors yields better results than allocation to sectors.

    作者

  • Simon Lansdorp - PhD, Portfolio Manager Sustainable Index Solutions

    Simon Lansdorp

    PhD, Portfolio Manager Sustainable Index Solutions

Factor investing uses a rules-based approach to isolate assets with certain characteristics that are expected to deliver superior risk-adjusted returns. Examples are stocks that are inexpensive relative to their fundamentals, stocks with strong recent performance, low-risk stocks, or high-quality stocks. Strategic allocation to such factors has been shown to provide diversification benefits and improve risk-adjusted returns over the more traditional portfolio management approaches that explicitly allocate to countries and/or sectors.

Interestingly, a recent working paper by Brierè and Szafarz (Factor-Based v. Industry-Based Allocation: The Contes, 2016) provides results of a contest between factor-based and sector-based investing. The authors conclude there is no clear winner between the two approaches in the long-only context. We challenge their conclusion and argue that results of the mentioned study are crucially dependent on the choice of factors that they consider. In fact, we show that an explicit allocation to the well-established factor premiums dominates allocation to sectors regardless of the optimization objective that is used.

Brierè and Szafarz (BS2016) consider the Size, Value, Momentum, and Quality factors and ten sectors, as classified by Kenneth French. While the authors show that factor investing is superior to sector investing within the long-short context, sector investing does as well, or even better than factor investing in the long-only context; i.e. when short-selling is not allowed. More specifically, the authors show that factor investing is the superior approach when evaluated using certain performance metrics, such as attaining the highest return, while sector investing beats factor investing when other performance metrics are used as the relevant evaluation criteria. For example, the paper claims that sector investing has the potential to offer greater downside protection than factor investing as strategies based on certain sector allocations are exposed to lower absolute risk levels than the best possible factor allocation.

Sector investing lacks a theoretical foundation

We oppose the idea that sector investing can add as much, or even more value than factor investing, even in the long-only context. First, there is no theoretical foundation for sector investing. While certain sectors have historically outperformed other sectors, there is no reason to expect this pattern will continue. Factor investing, on the other hand, is based on a vast amount of academic evidence that shows the existence of several factor premiums, provides reasons to expect these factors to continue to earn a premium in the future, and shows that factor-based strategies have added value in portfolios in practice.

Second, regardless of differences in the theoretical foundations, we argue that the empirical findings of BS2016 crucially depend on their selection of factors, and that conclusions turn in favor of factor investing if a different choice of factors is made. For instance, at Robeco, we believe in four key factor premiums that, next to Value, Momentum, and Quality, also includes the Low-Risk factor. The reason why BS2016 find that sectors have more potential to provide downside protection could well be because they do not include the Low-Risk factor in their selection. Consequently, the sector investing approach can be tilted to defensive sectors like utilities, but in their setting the factor investing approach is restrained from allocating to the defensive segment of the market.

Factor investing has superior results

We have ran our own horse-race between factor investing and sector investing, but this time also including a Low-Risk factor in the contest. We find that factor investing is superior to sector investing no matter what metric is used for performance evaluation. Moreover, the factor portfolios used in this analysis are based on very generic factor definitions. Using more sophisticated factor strategies is likely to give even better results, making the case in favor of factor investing even more compelling.

下載刊物

免責聲明

本文由荷宝海外投资基金管理(上海)有限公司(“荷宝上海”)编制, 本文内容仅供参考, 并不构成荷宝上海对任何人的购买或出售任何产品的建议、专业意见、要约、招揽或邀请。本文不应被视为对购买或出售任何投资产品的推荐或采用任何投资策略的建议。本文中的任何内容不得被视为有关法律、税务或投资方面的咨询, 也不表示任何投资或策略适合您的个人情况, 或以其他方式构成对您个人的推荐。 本文中所包含的信息和/或分析系根据荷宝上海所认为的可信渠道而获得的信息准备而成。荷宝上海不就其准确性、正确性、实用性或完整性作出任何陈述, 也不对因使用本文中的信息和/或分析而造成的损失承担任何责任。荷宝上海或其他任何关联机构及其董事、高级管理人员、员工均不对任何人因其依据本文所含信息而造成的任何直接或间接的损失或损害或任何其他后果承担责任或义务。 本文包含一些有关于未来业务、目标、管理纪律或其他方面的前瞻性陈述与预测, 这些陈述含有假设、风险和不确定性, 且是建立在截止到本文编写之日已有的信息之上。基于此, 我们不能保证这些前瞻性情况都会发生, 实际情况可能会与本文中的陈述具有一定的差别。我们不能保证本文中的统计信息在任何特定条件下都是准确、适当和完整的, 亦不能保证这些统计信息以及据以得出这些信息的假设能够反映荷宝上海可能遇到的市场条件或未来表现。本文中的信息是基于当前的市场情况, 这很有可能因随后的市场事件或其他原因而发生变化, 本文内容可能因此未反映最新情况,荷宝上海不负责更新本文, 或对本文中不准确或遗漏之信息进行纠正。