In finance, ESG stands for Environmental, Social, and Governance — a framework investors and analysts use to evaluate a company on factors that traditional financial statements do not capture, from carbon emissions and labor practices to board independence and executive pay. Global sustainable investment assets reached an estimated $39 trillion in 2025, and ESG data now feeds into ratings, fund construction, retirement plan decisions, and shareholder votes.
The framework does two things at once. It flags risks a balance sheet can miss, such as a supplier operating in a drought-stressed region or a board with weak independent oversight. And it gives investors a common vocabulary for comparing companies on non-financial performance.
What Each Letter Covers
The “E” measures a company’s impact on the natural world. Analysts track greenhouse gas emissions across three scopes: direct emissions from sources the company owns (Scope 1), indirect emissions from purchased electricity and heat (Scope 2), and emissions across the broader value chain, from suppliers to end users (Scope 3).1U.S. Environmental Protection Agency. Scope 1 and Scope 2 Inventory Guidance2GHG Protocol. Corporate Value Chain (Scope 3) Accounting and Reporting Standard Scope 3 often dwarfs the other two combined. Analysts also look at energy efficiency, waste diversion, and water withdrawal in cubic meters, particularly in water-stressed regions.
The “S” covers how a company treats employees, suppliers, customers, and communities. Common inputs include workforce turnover, the Total Recordable Incident Rate for workplace safety, diversity data across management levels, and customer privacy incidents.3Occupational Safety and Health Administration. Clarification on How the Formula Is Used by OSHA to Calculate Incident Rates The SEC also requires public companies to disclose the ratio of CEO pay to the median employee’s total compensation, a Dodd-Frank mandate, though the rule exempts emerging growth companies, smaller reporting companies, and foreign private issuers.4U.S. Securities and Exchange Commission. Pay Ratio Disclosure – Final Rule Supply chain review has widened too. The Tariff Act of 1930 bars imports produced with forced labor, and federal contracts over $500,000 performed abroad require a compliance plan addressing trafficking risks.5U.S. Department of Labor. Legal Compliance
The “G” looks at internal controls and shareholder protections. Analysts examine board independence, executive compensation structures disclosed on Schedule 14A proxy statements, audit committee expertise, and shareholder rights. Dual-class stock and anti-takeover provisions draw scrutiny because they can dilute ordinary shareholders’ voting power. Two newer governance metrics have become standard: cybersecurity oversight (SEC rules require Form 8-K disclosure of material cybersecurity incidents within four business days of a materiality determination, plus a description of the board’s role) and political spending transparency, including whether the board oversees contributions and lobbying.
How ESG Ratings Are Built
Third-party agencies convert this raw data into scores investors can compare across companies and sectors. The process usually begins with a review of public filings — 10-Ks, annual reports, proxy statements — supplemented by company surveys and monitoring of news, litigation, and regulatory records.
MSCI, one of the largest raters, uses a seven-band letter scale. A score between 8.571 and 10.0 on its internal scale earns an AAA “Leader” designation; a score between 0.0 and 1.429 gets a CCC “Laggard” label.6MSCI. MSCI ESG Ratings Methodology Other agencies use zero-to-100 scales. Different scales, same goal: producing numbers portfolio managers can plug into models.
Why Two Agencies Can Rate the Same Company Very Differently
The same company often receives sharply different scores from different raters. Academic research points to three drivers:
- Scope divergence — agencies weigh different sets of attributes. One may include lobbying activity; another ignores it.
- Measurement divergence — even for the same attribute, agencies use different indicators. One measures labor practices by turnover; another counts labor-related lawsuits.
- Weight divergence — agencies assign different importance to each attribute in the final score.
Measurement divergence drives about 56% of the total disagreement in these studies, scope divergence about 38%, and weight divergence roughly 6%. Researchers have also identified a “halo effect,” where a rater’s overall view of a company colors its scoring of individual categories. Checking more than one agency’s rating gives a more balanced picture.
Single vs. Double Materiality
Not every ESG framework defines “what matters” the same way. Single materiality — the traditional U.S. approach — asks only how environmental, social, and governance issues affect the company’s financial performance. Under this lens, a drought counts only if it threatens revenue or supply chain costs.
Double materiality adds a second question: how do the company’s operations affect society and the environment? The EU’s reporting standards generally follow this broader approach; most U.S. frameworks use single materiality. Which framework a rater or fund applies shapes what shows up in the analysis and what gets left out, so it is worth checking.
How Investors Use ESG Data
ESG information feeds into several distinct strategies, and they are not interchangeable:
- Negative screening excludes entire industries — tobacco, weapons, fossil fuels — from a portfolio. It is the oldest approach.
- Positive screening picks companies ranked at the top of their sector on ESG metrics rather than eliminating whole industries.
- ESG integration folds ESG data into standard financial analysis for every investment decision, without necessarily excluding any sector.
- Thematic investing targets specific trends such as renewable energy infrastructure or water technology.
Impact investing is often confused with ESG integration but sits apart. ESG integration is largely backward-looking, evaluating how a company has handled sustainability risks. Impact investing is forward-looking, defined by three features: intent to generate a measurable social or environmental benefit alongside financial returns, deliberate rather than incidental change, and a commitment to measuring the outcome. Most impact funds meet ESG standards; most ESG funds do not qualify as impact investments.
Shareholder Engagement
Investors also use ESG through active ownership. Under SEC Rule 14a-8, a shareholder who has continuously held at least $25,000 in a company’s stock for one year, or $2,000 for three years, can submit a proposal for inclusion in the company’s proxy statement.7U.S. Securities and Exchange Commission. Shareholder Proposals – Rule 14a-8 Companies can try to exclude proposals dealing with ordinary business matters, but proposals on broad policy issues such as climate strategy or workforce diversity generally survive. Even non-binding votes send a signal to management, and large institutional investors who cannot easily sell their positions rely heavily on this tool.
The Rules That Shape ESG in the United States
The U.S. regulatory picture is uneven, and knowing what is mandatory versus voluntary matters when you read fund materials or company disclosures.
The SEC Climate Disclosure Rule Is Not in Effect
In March 2024, the SEC adopted a rule that would have required public companies to disclose material climate-related risks and, for large filers, material Scope 1 and Scope 2 emissions.8U.S. Securities and Exchange Commission. The Enhancement and Standardization of Climate-Related Disclosures for Investors – Final Rule States and private parties challenged it, litigation was consolidated in the Eighth Circuit, and the SEC voluntarily stayed the rule.9Federal Register. The Enhancement and Standardization of Climate-Related Disclosures for Investors – Delay of Effective Date In March 2025, the Commission voted to withdraw its defense entirely.10U.S. Securities and Exchange Commission. SEC Votes to End Defense of Climate Disclosure Rules As of 2026, there is no mandatory federal climate disclosure requirement for U.S. public companies.
Fund Naming Rule
One federal rule that is in effect targets misleading labels. The SEC’s amended Investment Company Names Rule requires any fund whose name suggests an ESG or sustainability focus to invest at least 80% of its assets consistently with that focus under normal circumstances.11Federal Register. Investment Company Names Funds review their portfolios at least quarterly and have 90 days to return to compliance if they slip below the threshold. Terms used in a fund’s name must match their plain English meaning or established industry usage.
ERISA and Retirement Plans
If you manage or participate in an employer-sponsored retirement plan, the Department of Labor’s rules apply. Under ERISA, fiduciaries must select investments based on financial factors such as risk and return. A 2022 DOL rule clarified that climate change and other ESG factors may be considered when the fiduciary reasonably determines they are relevant to that risk-and-return analysis.12U.S. Department of Labor. Final Rule on Prudence and Loyalty in Selecting Plan Investments and Exercising Shareholder Rights The rule also sets a tiebreaker standard: when two options equally serve the plan’s financial interests over an appropriate time horizon, a fiduciary can pick the one with additional benefits such as favorable ESG characteristics. A fiduciary cannot accept reduced returns or greater risks to secure those collateral benefits.
State Anti-ESG Laws
Roughly 18 states have passed laws restricting the use of ESG considerations. They generally fall into two categories: prohibitions on state pension funds using ESG criteria, and “anti-boycott” laws restricting state contracts with financial institutions perceived to be boycotting industries like fossil fuels or firearms. If you work with a state pension fund or public money, these restrictions may directly affect which products you can use.
Greenwashing and What to Check
As ESG investing has grown, so has scrutiny of firms that overstate their sustainability credentials. The SEC has brought enforcement actions against advisers who misled investors about their ESG process. In 2023, the Commission charged DWS Investment Management Americas with materially misleading statements about its ESG integration; the firm agreed to pay $19 million for the ESG-related violations.13U.S. Securities and Exchange Commission. Deutsche Bank Subsidiary DWS to Pay $25 Million In 2024, the SEC charged Invesco Advisers with claiming that 70 to 94 percent of its parent company’s assets were “ESG integrated” when a substantial portion sat in passive funds that did not consider ESG at all; Invesco agreed to a $17.5 million civil penalty.14U.S. Securities and Exchange Commission. SEC Charges Invesco Advisers for Making Misleading Statements
The takeaway for anyone reading fund marketing: the label does not guarantee the process behind it. Look at the actual holdings, the prospectus language, ratings from more than one agency, and whether the fund has any enforcement history. That is what separates ESG as a real analytical framework from ESG as a marketing term.