Sustainable investing is a broad term for investment approaches that consider environmental, social and governance (ESG) issues alongside financial return. It covers strategies with quite different aims: some use ESG information to manage risk, some avoid industries on ethical grounds, and some seek to finance specific outcomes such as clean energy or affordable housing. Older and overlapping names include socially responsible investing (SRI), ethical investing and responsible investment.
Because the term is so wide, a fund calling itself sustainable says little on its own. Regulators in the European Union, the United Kingdom and the United States have therefore introduced disclosure rules, naming rules and labels that require managers to say which approach they use and to back their claims with evidence. The Principles for Responsible Investment (PRI), launched in 2006, is the largest investor network promoting the practice.
Sustainable investing in plain terms
Think of three shoppers in a supermarket who all say they "shop sustainably". One reads labels to avoid products likely to be recalled. Another refuses to buy anything from a company she disagrees with. A third goes looking for products that support local farmers. Each is acting on the same broad idea but with a different goal.
Sustainable investing is similar. The same phrase can mean careful risk checking, avoiding certain businesses or actively backing change, so the useful question is always: sustainable in what way, and how is that measured?
Main approaches
The Global Sustainable Investment Alliance has long grouped the strategies into seven families, which are often combined in a single fund:
- ESG integration. ESG integration builds material ESG factors into ordinary financial analysis.
- Negative or exclusionary screening. Exclusionary screening leaves out sectors or companies such as tobacco, controversial weapons or thermal coal.
- Positive or best-in-class screening. Best-in-class selection and a positive tilt favour the leaders within each sector.
- Norms-based screening. Companies are checked against international standards such as the UN Global Compact principles.
- Sustainability-themed investing. Thematic investing targets areas such as renewable energy, water or healthcare access.
- Impact and community investing. Impact investing aims at measurable social or environmental results alongside a return.
- Corporate engagement and shareholder action. Corporate engagement, proxy voting and resolutions are used to influence company behaviour.
History
Faith groups were early practitioners: Methodist and Quaker communities avoided businesses linked to slavery, alcohol or gambling, and the Pioneer Fund, launched in Boston in 1928, excluded alcohol and tobacco. The Pax World Fund (1971) was set up by investors opposed to the Vietnam War, and the 1980s campaign to divest from apartheid South Africa showed how investors could exert pressure. The Domini 400 Social Index followed in 1990. The term "ESG" was popularised by the UN-backed report Who Cares Wins in 2004, and the PRI followed in 2006. Faith-based approaches continue, notably in Islamic finance, where Sharia screens exclude interest-based lending and certain industries.
Fixed income joined later. The European Investment Bank issued a "Climate Awareness Bond" in 2007, and the market now includes green bonds, social bonds, sustainability bonds, sustainability-linked bonds and green sukuk. Many investors also align portfolios with the Paris Agreement or the UN Sustainable Development Goals (SDGs).
Labels, disclosure and greenwashing
In the EU, the Sustainable Finance Disclosure Regulation (SFDR) has applied since March 2021. Funds that promote environmental or social characteristics disclose under Article 8, and funds with a sustainable investment objective under Article 9; these were meant as disclosure categories but were widely used as labels. ESMA guidelines on fund names using ESG or sustainability terms applied from November 2024 for new funds and May 2025 for existing ones. In the UK, the FCA's Sustainability Disclosure Requirements created four voluntary labels, Sustainability Focus, Sustainability Improvers, Sustainability Impact and Sustainability Mixed Goals, usable from July 2024. In the US, the SEC amended its Names Rule in 2023 so that a mutual fund or ETF with an ESG-suggestive name must keep at least 80% of assets in line with it.
Enforcement has targeted overstated claims, known as greenwashing. In September 2023 the SEC charged DWS, Deutsche Bank's asset manager, over misstatements about its ESG process; DWS paid $19 million to settle that part of the case without admitting or denying the findings.
Performance and criticism
Whether sustainable funds earn more or less than conventional ones remains disputed. Results vary by period, sector weights and benchmark: excluding energy helped in some years and hurt in others, such as 2022 when oil and gas shares rose sharply. Critics point to inconsistent data, fees, the risk that labels mislead, and, since about 2021, political opposition in parts of the US. Supporters reply that investors have different goals, and that disclosure rules let them choose. For individual savers, the practical steps are to read how a fund defines its approach, check the holdings, and decide how it fits their investment objective and asset allocation.