What it means
SRI began with religious and charitable funds refusing to own certain industries, and it still rests on that idea of a line the investor will not cross. The mechanism is usually a negative screen, which is simply a rule excluding named sectors or companies from the investable universe.
It matters commercially because the money involved is substantial and increasingly institutional. Pension trustees, university endowments and family offices frequently write screening rules into their investment policy statements, which shapes which listed companies can attract that capital at all.
Practically, an investor picks between negative screening, positive or best-in-class screening, which favours the strongest performers within each sector, and impact investing, which targets a specific measurable outcome such as affordable housing units delivered. Most retail investors access it through a screened fund and pay a slightly higher management fee for the filtering work.
The performance question is the one everyone asks, and the honest answer is that a screen changes the risk profile rather than reliably improving or damaging returns. Excluding a whole sector concentrates the portfolio in what remains, so a screened fund can beat the market in one period and lag it in the next for reasons that have nothing to do with ethics.
The nuance that trips people up is that labels are not standardised. Two funds both described as socially responsible can hold very different portfolios, so the only reliable check is the fund's published exclusion policy and its actual top holdings.
In practice
Real-world examples.
Example
A university endowment votes to exclude thermal coal producers from its $400,000,000 portfolio and instructs its managers to complete the divestment over 18 months. The investment committee accepts a slightly higher tracking difference against its benchmark as the price of the policy.
Example
A pension scheme adopts best-in-class screening instead of outright exclusion, keeping energy exposure but holding only the producers with the strongest emissions and safety records. Trustees prefer this because it maintains sector diversification while still expressing a preference.
Example
A founder selling her business places $3,000,000 with an adviser and asks for no gambling or defence holdings. The adviser builds the portfolio from screened funds and provides an annual holdings report so the client can verify that the exclusions held.
Think of it
“SRI is investing according to your values-screening out companies that don't meet ethical standards.
Formula
Calculation
There is no single SRI formula, but the practical decision is a cost-of-screen calculation: Annual cost of screening = (benchmark return - screened return) x portfolio value + (screened fund fee - index fund fee) x portfolio value.
Consider an investor with $250,000 who wants to avoid tobacco, thermal coal and weapons. The broad index fund returned 7.5% for the year with a fee of 0.10%, while the screened fund returned 7.2% with a fee of 0.45%. The index fund would have produced $250,000 x 7.5% = $18,750, and the screened fund produced $250,000 x 7.2% = $18,000, a return difference of $18,750 - $18,000 = $750.
On fees, the screened fund charged $250,000 x 0.45% = $1,125 against the index fund's $250,000 x 0.10% = $250, an extra $1,125 - $250 = $875. The total cost of applying the screen for that year was $750 + $875 = $1,625, or 0.65% of the portfolio. Whether that is worth paying is a values judgement, not an arithmetic one, but at least the investor now knows the price.Case study
Seen in the real world.
The Rowan Trust is an illustrative, fictional charitable foundation with $60,000,000 invested to fund children's health grants. Its trustees were embarrassed when a supporter pointed out that the foundation held shares in a tobacco group, which sat awkwardly with the mission.
The trustees adopted a written exclusion policy covering tobacco, gambling and controversial weapons, then asked their manager to model the effect. The modelling suggested the screen would have reduced returns by roughly 0.3% a year over the previous decade and raised fees by 0.35%, costing around $390,000 annually on the current portfolio.
In this fictional case the trustees accepted the cost explicitly and minuted the reasoning, on the grounds that a health charity funded by tobacco profits carried a reputational risk they valued at more than $390,000. The important point is that they priced the decision rather than assuming it was free.
Watch out
Common mistakes.
- Assuming SRI and ESG mean the same thing. SRI usually excludes on values grounds, while ESG scoring is generally used to analyse risk and can still hold a company others would exclude.
- Buying a fund on its name alone. Exclusion policies vary widely, and a fund labelled sustainable may still hold companies the investor expected to be screened out.
- Expecting a screen to be free. Screened funds usually charge more and will drift from the broad market, sometimes helpfully and sometimes not.
Questions
People also ask.
Does socially responsible investing reduce returns?
Not systematically, but it does raise fees and concentrate the portfolio, so results diverge from the benchmark in both directions.
What is the difference between negative and positive screening?
Negative screening removes named sectors entirely, while positive screening keeps every sector but favours the best performers within each one.
Can a small investor do this without a specialist adviser?
Yes, several mainstream index providers publish screened versions of standard indices, and the exclusion rules are available in the fund documents.
From the founder's library
Take it further with the book.
Build your financial confidence beyond this definition. Shihan's full-length guide, Accounting Fundamentals, takes the same plain-English approach and turns it into a complete, practical playbook for non-finance managers, business owners and students - with chapter-end quiz answers and presentation slides included.
25% off with code MMHQ25, applied at checkout. Priced in USD - checkout may show the equivalent in your local currency.
View the book and save 25%