ESG Investing

ESG investing is the practice of selecting or weighting investments by reference to environmental, social and governance factors alongside financial ones. The Securities and Exchange Commission's investor glossary states it directly: "'ESG' stands for environmental, social, and governance. ESG investing is a way of investing in companies based on their commitment to one or more ESG factors. It is often also called sustainable investing, socially responsible investing, and impact investing."

That last sentence is worth pausing on, because it settles a naming question the industry generally leaves open. The SEC treats the four phrases as names for one thing. Practitioners frequently distinguish them: socially responsible investing is often used to mean excluding categories of company, ESG to mean incorporating those factors into the analysis of a company, and impact investing to mean pursuing a measurable outcome and sometimes accepting a lower return to do so. Those distinctions are real in the sense that people use them, and they are conventions rather than definitions. No regulator assigns a fund to one of them, and two funds using the same word may not mean the same thing by it.

The one place US law currently bites is the name on the fund, and the rule reaches ESG by name. Rule 35d-1 under the Investment Company Act, at 17 CFR 270.35d-1(a)(2), treats a fund name as materially deceptive and misleading if it includes terms suggesting a focus on investments or issuers with particular characteristics, and the rule's own example of such terms is "a name with terms such as 'growth' or 'value,' or terms indicating that the fund's investment decisions incorporate one or more environmental, social, or governance factors." So ESG is not an afterthought in the rule; it is one of the two illustrations the text offers.

A fund with such a name escapes that characterization only by adopting a policy to invest, under normal circumstances, at least 80% of the value of its assets in accordance with the investment focus the name suggests. Two further conditions attach. The policy must either be a fundamental policy or the fund must undertake to give shareholders at least 60 days' notice before changing it, along with any accompanying change of name. And under paragraph (a)(2)(iii), any term in the name suggesting that focus must be "consistent with those terms' plain English meaning or established industry use." The general mechanics of how the 80% basket is maintained are covered on the page for growth stocks, where the same rule does the same work for a different word.

What follows from that is the single most useful thing to understand about ESG funds. The rule does not define ESG. It requires each fund using the word to define it in its own documents, to place the bulk of the portfolio behind that definition, and to use the word in a way consistent with its plain English meaning or established industry use. The definition is the fund's; the obligation to have one and to stand behind it is the rule's. Two funds with similar names can therefore hold materially different portfolios while both complying, and the document that resolves the difference is the prospectus rather than the name.

The compliance timing matters because the amended rule is phasing in now. The Commission stated in February 2026 that the compliance dates for the amendments adopted in September 2023, other than the Form N-PORT reporting amendments, "will remain June 11, 2026, for fund groups with net assets of $1 billion or more as of the end of their most recent fiscal year and December 11, 2026, for fund groups with less than $1 billion in net assets as of the end of their most recent fiscal year." So the requirement arrives in two stages and the schedule completes in December 2026. The related reporting on Form N-PORT was separately extended further, to November 2027 for the largest fund groups and May 2028 for the rest.

Now the part that most published material about ESG still gets wrong. The SEC proposed a dedicated ESG disclosure regime in June 2022, which would have required funds and advisers to disclose their ESG practices and which set out a three-part classification of ESG funds into integration, ESG-focused and impact categories. That proposal was formally withdrawn on 17 June 2025. The withdrawal notice states that the Commission "does not intend to issue final rules with respect to these proposals," and that if it decides to pursue future regulatory action in any of these areas, "it will issue a new proposed rule."

The three-way classification therefore has no legal force and never had any. It was a proposal that was abandoned. A reader who has met that classification and taken it for a standard has met a description of a rule that was never adopted, which is worth knowing before using it to compare two funds. What is left is the names rule, which regulates the label rather than the practice, and the ordinary disclosure obligations that apply to any fund.

The practical consequence for anyone evaluating one of these funds is that the label carries less information than it appears to, and the fund's own documents carry more. The 80% policy has to be stated, so the prospectus will say what the fund counts toward it. Reading that statement, and then the holdings, answers a question the name cannot. Where a fund's approach involves excluding sectors or companies, the portfolio is by construction narrower than the broad market it is drawn from, which is a mechanical fact about diversification rather than a judgment about the approach.

A fund adopts an investment approach that takes environmental, social or governance factors into account, states in its prospectus what that means and how it is applied, and, if its name suggests such a focus, adopts a policy to invest at least 80% of the value of its assets accordingly. An investor evaluating it reads the stated policy, then the definition behind it, then the holdings, and compares those with the alternatives.

A hypothetical example of two funds that both comply and hold different things. Two funds of similar size carry near-identical sustainability names, so the names rule obliges each of them to place at least 80% of the value of its assets behind the focus its name suggests.

The first fund's prospectus defines that focus by exclusion, screening out several named industries and holding what remains of a broad index. The second's defines it by ranking, keeping companies that score well on a data provider's environmental and governance measures and excluding no sector outright. Each has placed the required proportion inside its own stated policy, and each is complying with the rule. Their holdings can nonetheless overlap very little, and each is free to invest the remainder outside the focus altogether.

Nothing in the names rule resolves that difference, because what the rule requires is that a fund have a definition and stand behind it, not that it use anyone else's. The document that resolves it is the prospectus, and reading the two stated policies side by side is exactly the step the similarity of the two names invites an investor to skip.

Pros

• The names rule gives a concrete, checkable obligation behind a word that otherwise carries no fixed meaning, and it requires the fund to write its own definition down.
• Because each fund must state its policy, an investor willing to read the prospectus can find out exactly what a fund counts and what it does not.
• The approach lets an investor align a portfolio with stated preferences within a conventional, regulated fund structure.
• Governance factors in particular concern how a company is run and overseen, which is a subject with a long history in ordinary financial analysis.

Cons

• No standard definition governs the term, so the same word can describe very different portfolios and comparison requires reading the documents.
• The three-part classification of these funds that a reader may have met comes from a proposal the SEC withdrew in 2025, so it has no legal force despite being easy to mistake for a standard.
• Screening narrows the investable universe relative to the broad market it is drawn from, which reduces diversification by construction.
• Up to a fifth of a fund's assets need not fit the focus its name suggests, which the name does not disclose.
• The expense ratio has to be compared against a broad index alternative before buying, because that cost applies every year whatever else happens.