Our Approach to Building an SRI Portfolio


  • Many investors prefer to invest according to their values. Socially and environmentally conscious customers can now take advantage of our Socially Responsible Investing (SRI) option.
  • SRI portfolios are expected to track Betterment core portfolios closely in terms of performance.
  • Despite the nascent state of SRI, Betterment’s portfolio represents a diversified, low-cost SRI solution that will be improved as data, costs, and SRI funds improve.



In today’s market, there are many challenges to address when building a socially responsible investing (SRI) portfolio. The most significant of these challenges: SRI is still an emerging field, and its growing demand is a relatively recent phenomenon.


Our approach to SRI is aspirational. We’ve created a portfolio strategy designed to be iterated on over time, without sacrificing core principles of our advice: balanced cost and proper diversification.

To develop our SRI portfolio, we had to research, analyze, and ultimately answer five important questions:

  • How should we define SRI for this portfolio?
  • What are the challenges for implementing SRI today?
  • Which SRI funds belong in an effective portfolio?
  • How should we assess the “social responsibility” of an SRI portfolio?
  • Should we expect any difference in an SRI portfolio’s performance?

The resulting answers to these questions, explained in the sections that follow, informed how we created the SRI Portfolio for our customers.

  1. How do we define SRI?

Our approach to SRI has two fundamental dimensions:

  • Reducing exposure to companies involved in non-socially responsible activities and environmental, social, or governmental controversies.
  • Increasing investments in companies that work to address solutions for core environmental and social challenges in measurable ways.

We chose to define our SRI approach using a set of industry criteria known as ESG, which stands for Environmental, Social and Governance. You may have seen SRI and ESG used interchangeably in financial literature. But experts will point out that there is a clear distinction between how each term is defined. ESG refers specifically to the quantifiable dimensions of socially responsible investing among each of the three components. In our SRI portfolio, we use ESG factors to define and score the degree to which our portfolio is socially responsible.


Using ESG Factors to Define an SRI Approach

A significant and obvious aspect of improving a portfolio’s ESG score is reducing exposure to companies that engage in undesirable activities in your investment portfolio. Companies can be undesirable because their businesses do not align with specific values—e.g. selling tobacco, military weapons, or civilian firearms.

Other companies may be undesirable because they have been involved in recent and ongoing ESG controversies and have yet to make amends in a meaningful way.

ESG controversies include:


But SRI is about more than just adjusting your portfolio to minimize companies with a poor social impact. Based on the framework of MSCI, a leading provider of ESG data and analytics, a socially responsible investment approach also emphasizes the inclusion of companies that have a high overall ESG score, which represents an aggregation of scores for multiple thematic issues across E, S and G pillars as shown in Table 1 below.

Table 1. A Broad Set of Criteria Across E, S and G pillars

3 Pillars 10 Themes 37 Key ESG Issues
Environment Climate Change Carbon Emissions

Energy Efficiency

Product Carbon Footprint

Natural Resources Water Stress

Biodiversity & Land Use

Pollution & Waste Toxic Emissions & Waste

Electronic Waste

Packaging Material & Waste

Environmental Opportunities Opportunities in Clean Technology

Opportunities in Renewable Energy

Opportunities in Green Building

Social Human Capital Labor Management

Human Capital Development

Health & Safety

Supply Chain Labor Standards

Product Liability Product Safety & Quality

Privacy & Data Security

Chemical Safety

Responsible Investment

Financial Product Safety

Health & Demographic Risk

Stakeholder Opposition Controversial Sourcing
Social Opportunities Access to Communications

Access to Health Care

Access to Finance

Opportunities in Nutrition & Health

Governance Corporate Governance Board*




Corporate Behavior Business Ethics

Corruption & Instability

Anti-Competitive Practices

Financial System Instability

* Board, Pay, Ownership, and Accounting carry weight in the ESG Rating model for all companies. Currently, they contribute to the Corporate Governance score directly and 0-10 sub-scores are not available.


Source: MSCI

  1. The State of Socially Responsible Investing in 2017

Although using ESG factors to select portfolio funds may sound like a brilliantly straightforward, quantitative approach to constructing a portfolio, unfortunately, in today’s market, there are a number of limitations that plague the process of executing SRI. In spite of these limitations, we still maximize the expression of your SRI values with the best available investing tools.

For Betterment, three limitations had a large influence on our overall approach to building an SRI portfolio:


  1. Poor quality data underlying ESG scoring.


Because SRI is still gaining traction, data for constructing ESG scores are at a nascent stage of development. There are no uniform standards for data quality yet.

Some companies disclose data on the various ESG metrics, others don’t. And companies that do disclose their data may do so in inconsistent ways. As a result, ESG metrics may not necessarily capture the desired concepts and ideals with 100% accuracy.

In order to standardize the process of assessing companies’ social responsibility practices , Betterment uses ESG factor scores from MSCI, an industry-leading provider of financial data and ESG analytics that has served the financial industry for more than 40 years. MSCI collects data from multiple sources, company disclosures and over 1600 media sources monitored daily. They also employ a robust monitoring and data quality review process.[1] By adopting MSCI’s framework for calculating ESG metrics, we’re putting our best foot forward toward assuring the data is as accurate as currently possible.


  1. Many existing SRI products on the market have serious shortcomings.

Many SRI portfolio products today can be categorized in one of two ways:

  • Products that sacrifice sufficient diversification required by long-term investors.
  • Products that invest based on competing ESG issues/themes, resulting in inconsistent SRI principles.

Some solutions do not use a diversified range of asset classes—for example, holding mostly or entirely US large cap stocks–or invest only in individual stocks. At Betterment, diversification is a fundamental pillar of our advice, and we do not believe it’s in an investor’s best interest to offer an under-diversified portfolio.

In the second case, some SRI firms aim to promote specific ESG issues or themes using a combination of SRI ETFs. Too often, however, this approach leads to offsetting positions in the same asset class, reducing the focus and effectiveness of the portfolio. For example, a portfolio that holds the SHE ETF, which invests in companies that rate highly in terms of gender diversity, currently holds Pfizer stock. The DSI ETF, however, screens out Pfizer from its stock holdings (as noted below). Any SRI portfolio that held both of these ETFs would not achieve either ETF’s intention regarding whether an investor should hold Pfizer stock. This is the pitfall of an SRI approach that lacks a coherent methodology within an asset class. Our approach has the advantage that it leads to diversified portfolios at relatively low cost. Our SRI portfolios are also built around ETFs that capture a broad set of ESG themes based on one coherent methodology for US large-cap stocks. As such, we do not expect to run into the contradictory SRI exposures within the same asset class resulting from holding multiple SRI ETFs that each focus on different ESG themes. This broad ESG theme coverage may not meet the needs of every investor, but it has major advantages for long-term investors over other approaches.


  1. Few SRI-oriented ETFs have sufficient liquidity.

In an effort to control the overall cost for SRI investors, a large portion of our research focused on low-cost exchange-traded funds (ETFs) oriented toward SRI. As with any of our portfolios, we aim to maximize investors’ take-home returns by lowering the costs of the underlying funds.

While SRI-oriented ETFs indeed have relatively low expense ratios compared to SRI mutual funds, our analysis quickly revealed insufficient liquidity in many ETFs currently on the market. Without sufficient liquidity, every trading execution becomes more expensive, creating a drag on returns.

Median daily dollar volume is one way of measuring liquidity. Higher volume on a given asset means that you can quickly buy (sell) more of that asset in the market without driving the price up (down). Of course the degree to which you can drive the price up or down with your buying or selling must be treated as a cost that can drag down on your returns. Figures 1 and 2 below put the liquidity issues associated with trading two SRI ETFs, DSI and KLD, into perspective by comparing their liquidity to the liquidity of other ETFs used in our portfolios.

In balancing cost and value for the SRI portfolio, the options were limited to funds that focus on US stocks with large market capitalization—also referred to as US Large Cap stocks.

Accordingly, DSI and KLD are the two ETFs with SRI mandates that we have selected for the SRI portfolio. Across all options for SRI oriented ETFs, they have the largest AUM and our investment selection process shows that they have the highest liquidity.Figure

Figure 1. Liquidity in DSI and KLD pales in comparison.

Figure 1. In this figure we compare the median daily dollar volumes of the primary funds in current Betterment core IRA portfolios against those of DSI and KLD. As you can see, every fund that we currently trade in the Betterment portfolios has liquidity that far surpasses that of DSI or KLD.


Figure 2. DSI and KLD are much more liquid than other ETFs with SRI mandates.


Figure 2. DSI and KLD are far more liquid than other fund options with SRI mandates. ESGD is the equivalent of DSI for equity markets in international developed countries. Similarly, ESGE is the SRI-oriented ETF for emerging market stocks. Both of these ETFs have substantially lower liquidity than their US counterparts and were not considered viable for trading based on our total cost to trade metrics. Similarly, SRI oriented bond ETFs also lack sufficient liquidity. Currently, GRNB is the only green bond fund we are aware of, and the market for these funds will need to develop further before there are a sufficient number of funds with sufficient liquidity to make them candidates for inclusion in Betterment’s SRI portfolio.


III. How is Our SRI portfolio constructed?


We are taking steps toward socially responsible investing even if the currently available fund products do not necessarily present the ideal solutions. Overall, in order to meet our requirements for lower cost and higher liquidity, our SRI portfolio focuses on large US companies that rate highly on a scale that considers all three ESG pillars. In order to maintain geographic diversification and factor tilts toward value and smaller cap companies, we continue to allocate to funds that do not have SRI mandates.


How does the SRI portfolio compare to our core portfolio?

When compared to our core portfolio, the main change to both taxable and tax-deferred portfolios is the replacement of our current US large cap stock exposures with an allocation to a broad US ESG stock market ETF (DSI). Another broad US ESG stock market ETF (KLD) serves as the secondary ticker for DSI, which is utilized by Tax-Loss Harvesting+.

DSI and KLD each track a benchmark index that screens out companies involved in specific activities and selectively includes companies that score relatively highly across a broad set of ESG metrics [2]. The benchmark index for DSI explicitly filters out companies involved in tobacco, military weapons, civilian firearms, GMOs, nuclear power, alcohol and adult entertainment. KLD’s benchmark index screens out tobacco companies and companies that have run into recent ESG controversies (a few examples were mentioned earlier).

Our value and small cap factor tilts, as well as our allocations to international stocks and bonds, continue to be expressed using non-SRI focused ETFs since either the corresponding SRI alternatives do not exist or lack sufficient liquidity. These non-SRI funds continue to be part of the portfolios for diversification purposes.

An example of a Betterment SRI portfolio for IRA accounts at a 70% stock allocation, with its primary tickers, is shown in Figure 3. Taxable portfolios are similar but with the replacement of US total bond market exposure (BND primary) by US municipal bonds (MUB primary) as is implemented currently for Betterment core portfolios.

Figure 3. SRI Portfolio for IRA – 70% Stock Allocation

Based on the primary ticker holdings, the following are the main differences between Betterment’s SRI portfolios and core portfolios:

  • Removal of exposures to the US total stock market (VTI) and US large cap value (VTV).
  • Incorporation of DSI in order to replace the US large cap stock exposures within VTI. DSI also completely absorbs the allocation to VTV of Betterment core portfolios.
  • Addition of VOT and VBK in order to account for mid cap and small cap growth allocations within VTI.
  • Maintenance of allocations to VOE and VBR so as to account for the mid cap and small cap value allocations within VTI and the value tilt of Betterment core portfolios.

SRI portfolios can also support our core products for increasing after-tax returns, Tax-loss Harvesting+ (TLH) and Tax-coordinated portfolios (TCP). For the ETFs with SRI mandates, while DSI and KLD serve as primary and secondary tickers, respectively, IVV is the corresponding tertiary ticker (i.e., the secondary ticker for DSI in an IRA portfolio). IVV is an ETF that is benchmarked against the S&P 500 and is not weighted screened for ESG factors. IVV is incorporated solely to maximize the benefits of TLH and manage the wash sale rule, and is only held in limited cases.


Limitations of Our Approach

The ESG Scoring approach to SRI does not fully eliminate companies that investors interested in SRI may consider undesirable. As of the end of May of 2017, for example, both DSI and KLD included some energy companies that engage in oil and natural gas exploration, like Hess. While Hess might rate relatively poorly in terms of the “E” of ESG, it could still rate highly in terms of the “S” and the “G.” Furthermore, for diversification purposes, we’re still holding funds in the portfolios that do not have SRI mandates for international stock and both domestic and international bond exposure, as mentioned earlier.

The limitations of our approach and the available SRI products leave room for improvement, but we are committed to achieving more socially responsible investing through our research over time and are tracking the availability of better vehicles for these purposes. This is simply the beginning of a conversation: customers interested in SRI can signal to the investing world that there is a demand for high quality SRI investment options and may help to encourage the development of well-diversified, low-cost SRI funds in a wider variety of asset classes.

We ask our customers to join us on this journey and will provide periodic updates on our progress.

  1. How socially responsible is the SRI portfolio?

The stocks of US large cap companies deemed to have a negative social impact are clearly removed from the SRI portfolio. As of July 3, 2017, companies such as BP, Exxon, Chevron, Philip Morris, Wells Fargo, Walmart and Pfizer are not among the stock holdings of the SRI portfolios. [3] Exclusion of the stocks of BP, Exxon and Chevron is obvious, as they are all oil companies. So is the exclusion of the stock of a large tobacco company like Phillip Morris. Wells Fargo, Walmart, and Pfizer all suffer from scoring poorly in terms of the social dimension and/or corporate governance, [4] according to ESG scores.

As mentioned earlier, we use the ESG data and analytics from MSCI to quantify how SRI oriented your portfolios are. For each company that they cover, MSCI calculates a large number of ESG metrics across multiple E, S, and G pillars and themes (recall Table 1 above). All these metrics are first aggregated at the company level to calculate individual company scores. At the fund level, an overall MSCI ESG Quality score is calculated based on an aggregation of the relevant company scores. This fund level ESG Quality score reflects “the ability of the underlying holdings to manage key medium- to long‐term risks and opportunities arising from environmental, social, and governance factors” [5]. These fund scores can be better understood given the MSCI ESG Quality Score scale shown below.

Table 2. The MSCI ESG Quality Score Scale

The ESG Quality Score measures the ability of underlying holdings to manage key medium- to long-term risks and opportunities arising from environmental, social, and governance factors.
Scale 0-10 Score
8-10 Very high ESG quality — underlying holdings largely rank best in class globally based on their exposure to and management of key ESG risks and opportunities
6-8 High ESG quality — underlying holdings largely rank above average globally based on their exposure to and management of key ESG risks and opportunities
4-6 Average ESG quality — underlying holdings rank near the global peer average, or ESG quality of underlying holdings is mixed
2-4 Low ESG quality< — underlying holdings largely rank below average globally based on their exposure to and management of key risks and opportunities
0-2 Very low ESG quality — underlying holdings largely rank worst in class globally based on their exposure to and management of key ESG risks and opportunities

Source: MSCI

Based on data from MSCI courtesy of etf.com, the US large cap stock holdings of our SRI portfolios have an MSCI ESG Quality score that is approximately 42% higher on average relative to those of Betterment core portfolios. The data shown in Table 3 and the scale presented in Table 2 show that, on average, while current Betterment core portfolios hold US large cap stocks that are of Average ESG quality, SRI portfolios invest in US large cap stocks that are of high ESG quality.

Table 3. MSCI ESG Quality Scores

US Large Cap Equity Holdings in the Core Portfolio vs. ETF tickers in the SRI Portfolio
Betterment Portfolio – US Large Cap DSI KLD
5.039 6.34 8.01

Sources: MSCI courtesy of etf.com


A Note on ESG Risks and Opportunities

An ESG risk captures the negative externalities that a company in a given industry generates that may become unanticipated costs for that company in the medium- to long-term. An example of such a risk is the possible need to reformulate if a company’s product due to a regulatory ban on a key chemical input. An ESG opportunity for a given industry is considered to be material if companies will capitalize over a medium- to long-term time horizon [6]. Examples of ESG opportunities include the use of clean technology for the LED lighting industry.

For a company to score well on a key ESG issue (see Table 1 again for examples), both the exposure to and management of ESG risks are taken into account. The extent to which an ESG risk exposure is managed needs to be commensurate with the level of the exposure. If a company has high exposure to an ESG risk, it must also have strong ESG risk management in order to score well on the relevant ESG key issue. A company that has limited exposure to the same ESG risk, only needs to have moderate risk management practices in order to score as highly. The converse is true as well. If a company that is highly exposed to an ESG risk also has poor risk management, it will score more poorly in terms of ESG quality than a company with the same risk management practices, but lower risk exposure.

For example, water stress is a key ESG issue. Electric utility companies are highly dependent on water with each company more or less exposed depending on the location of its plants. Plants located in the desert are highly exposed to water stress risk while those located in areas with more plentiful water supplies present lower risk. If a company is operating in a location where water is scarce, it needs to take much more extensive measures to manage this risk than a company that has access to abundant water supply.

  1. Should we expect any difference in an SRI portfolio’s performance?

One might expect that a socially responsible portfolio could lead to lower returns in the long term compared to another, similar portfolio. The notion behind this reasoning is that somehow there is a premium to be paid for investing based on your social ideals and values.

A study by the Royal Bank of Canada (RBC) from 2012, however, shows that based on a comprehensive literature review, this claim is questionable at best. This paper summarizes the results from 16 different SRI studies and in most cases, the performance of SRI funds did not differ significantly from that of non-SRI funds. The authors of the RBC study also show, as in Figure 4, that the KLD 400 Index (i.e., the benchmark index for DSI) slightly outperformed the S&P 500 (the quintessential benchmark for US large cap stocks) over the period April 1990 to April 2012. They note however that the return between the two indices can be meaningfully different, in both positive and negative directions, over shorter time periods. For example, the authors claim that, over one year periods, return differences of ± 2% are common and can be as large as ± 5%.

Figure 4. KLD 400 vs. S&P 500 – April 1990 to April 2012

Source: Royal Bank of Canada

When considering the possible performance of SRI portfolio, we examined evidence based on both historical and forward-looking analyses. When adjusting for the stock allocation level, the data indicate that the performance of Betterment’s SRI portfolio versus our core portfolio is not significantly different.

Backtests Based on Historical Returns

Past performance does not guarantee future results. Nonetheless, our analysis of historical returns is consistent with our assertion that the performance of SRI portfolios should track the performance of the core portfolios very closely. An analysis of the historical total gross returns over the past ten years [7] shows that SRI portfolios and core portfolios have been very highly correlated. In Figure 5 we illustrate this high correlation using IRA portfolios at a 70% stock allocation as an example. Both Taxable and IRA portfolios exhibit similar properties given other stock allocation levels.

Figure 5. Backtested returns are highly correlated.

Based on historical returns of a 70% stock allocation portfolio gross of all fees for the period ending June 30, 2017.

But how do the net returns compare? In Figure 6 we show that the weighted expense ratios of SRI portfolios are higher than those of core portfolios at non-zero stock allocation levels (and the spread increases as you add more stocks to the mix). You might expect that the higher expense ratios would drag down the net performance of SRI portfolios relative to core portfolios.

Figure 6. Weighted Expense Ratios for all IRA Portfolio Allocations

Sources: Factset and author’s calculations as of 2017-05-15

As it turns out, after reducing returns both by weighted expense ratios and a annual firm fee, the performance of SRI portfolios ended up being about the same as that of core portfolios for the recent ten year period ending on June 30, 2017. Table 3 provides an example of this claim for IRA portfolios at a 70% stock allocation. Performance summaries for other stock allocation levels as well as for taxable portfolios look similar.

Table 4. Comparing Net Performance

70% Stock Allocation Portfolios for Ten Year Period ending June 30, 2017
Portfolio SRI Portfolio
Annualized Return (net) 4.51% 4.48%
Annualized Standard Deviation 12.91% 12.85%

Source: Xignite, author’s calculations

Forward-looking Analysis

In Figure 7, we graph expected net total returns at each risk (stock allocation) level for both Betterment core and SRI portfolios. All expected total returns are expressed in annual terms and are net of the portfolio weighted ETF annual expense ratios and Firm fee. Based on the application of Black-Litterman and mean-variance portfolio optimization methods, they are our best estimates of the actual returns, net of known fees, that you can expect to achieve on average annually. The expected net total returns of SRI portfolios are only slightly below those of Betterment core portfolios. The higher weighted expense ratios of SRI portfolios primarily account for their expected underperformance.

Figure 7. Comparison of Efficient Frontiers

Assumes a risk-free rate of 1.63%

Sources: Market capitalization data collected from S&P Dow Jones Indices , SIFMA , and Bank for International Settlements. Price data are from Yahoo Finance. A risk-free rate assumption of 1.63% is for a 10-year horizon and is derived using our methods for estimating the forward curve. Calculations are by the Betterment Investing Team.

Dividend Yields could be Lower

Dividend yields calculated over the past year ending June 30, 2017 indicate that income returns coming from SRI portfolios have been lower than those of core portfolios recently (see Figure 8). Oil and gas companies like BP, Chevron, and Exxon, for example, currently have relatively high dividend yields and excluding them from a given portfolio can cause its income return to be lower. Of course, future dividend yields are random variables and past data may not provide accurate forecasts. Nevertheless, lower dividend yields can be a factor in driving total returns for SRI portfolios to be lower than those of core portfolios.

Figure 8. Comparison of Dividend Yields

Source: Yahoo Finance, author’s calculations for one year period ending June 30, 2017



SRI portfolios are designed to help you express your values and social ideals through your investments. Despite the various limitations that SRI portfolios face today, Betterment wants to support its customers in meeting their desires for more socially responsible vehicles for investing. We are now able to provide you with a globally diversified SRI portfolio at relatively low cost that is expected to track the performance of long-standing core portfolios closely. You can think of this current SRI product offering as only the start of our SRI journey. We are actively seeking to make this product more socially responsible over time as demand grows for the relevant products and as new SRI solutions become available. By expressing your preference for SRI investment products through your portfolio, you can play a significant role in making that happen. Stay tuned.

[1] See the ESG Ratings Methodology Executive Summary for more detail.

[2] DSI’s benchmark index is the MSCI KLD 400 Social Index. For more details on its construction see the MSCI methodology. KLD’s benchmark index is the MSCI USA ESG Select Index. More detailed information on its construction methodology can be found here.

[3] Data courtesy of BlackRock / iShares as of July 3, 2017.

[4] See http://www.businessinsider.com/companies-with-bad-esg-scores-2012-10 for example. Note that Wells Fargo has also been embroiled in a scandal involving the creation of fake customer accounts.

[5] See https://www.msci.com/esg-fund-metrics for more detail.

[6] See MSCI ESG Ratings Methdology (February 2017) for more detail.

[7] Total gross returns are monthly and correspond to the ten-year period ending June 30, 2017. Historical total gross returns include dividends and are gross of fund fees and the annual firm fee.