Industry classification: GICS, ICB, TRBC and other groupings

What are industry classification schemes?

The first step of industry analysis is deciding which companies belong together. An industry is commonly defined as the companies that sell similar products or services, seen from the customer’s point of view. Applying that is harder than it sounds, so analysts start from a third-party scheme.

The oldest schemes, the Standard Industrial Classification (SIC), the Statistical Classification of Economic Activities in the European Community (NACE) and the International Standard Industrial Classification of All Economic Activities (ISIC), were built by government agencies. They are country-specific, group companies by how they produce things (agriculture, manufacturing, retail, services) and were revised rarely. They fell behind as new technologies and business models appeared and as issuers and investors became global. Commercial schemes largely replaced them:

• The Global Industry Classification Standard (GICS) , from MSCI and S&P Dow Jones Indices (S&P stands for Standard & Poor’s).
• The Industry Classification Benchmark (ICB) , from FTSE Russell.
• The Refinitiv Business Classification (TRBC) , from Refinitiv.

Industry classification schemesa starting point for defining an industry

• Legacy government schemes Use it SIC, NACE, ISIC
  • Basis: production characteristics the "supply" view
  • Country-specific built by government agencies
  • Updated infrequently fell behind new business models
• Commercial schemes Memorize GICS, ICB, TRBC
  • Basis: similarity of products sold Memorize the "demand" view
  • Global GICS and ICB cover public companies; TRBC also private, non-profit, government
  • Reviewed at least annually Memorize new companies added more often
  • Strictly hierarchical Memorize each company sits in one lowest-tier group

All three are global, reviewed at least annually (new companies are added more often) and group by product similarity, a demand view rather than the supply view of the legacy schemes. GICS and ICB cover public companies. TRBC also covers private companies, non-profits and government bodies.

How are companies placed in the hierarchy?

The three schemes are each a strictly hierarchical taxonomy , like the species, genus and family ranking in biology. A company is placed in one group at the lowest tier, and that placement fixes its groups at every higher tier. GICS runs from sector to industry group, industry and sub-industry; the other two use their own tier names.

A company with one line of business is placed by that business. A company with several segments is usually placed by the segment that supplies the majority of its revenue, profit or assets. If no segment clearly does, the provider uses judgment or labels the company a conglomerate or multi-industry. The aim is a single grouping that describes most of the business.

Go deeper How many tiers does each scheme have?

Know that the three differ in names and depth, not the exact counts. For reference: GICS has 11 sectors, 25 industry groups, 74 industries and 163 sub-industries. ICB has 11 industries, 20 supersectors, 45 sectors and 173 subsectors. TRBC has 14 economic sectors, 33 business sectors, 62 industry groups, 154 industries and 898 activities. The first tier of all three is similar: energy, financials, materials, technology, industrials, communications, consumer discretionary, utilities, consumer staples, real estate and health care. TRBC adds three sectors for institutions, government activity and education.

Where do the standard schemes fall short?

Memorize

A scheme is a starting point. Four limitations matter, and each one has a typical exam clue.

Limitations of GICS, ICB and TRBCcheck that classified companies really compete

• Groupings too broad or too narrow Memorize business model variations and substitutes
• Multi-product companies Memorize one box per company, so a competitor may sit in another sector
• Geography Memorize global groups fit global industries, not local services
• Changes over time Memorize reclassifications, listings and delistings hurt comparability and add survivorship bias

1. Groupings too broad or too narrow. Two companies filed under “specialty chemicals”, one making paint additives and one making battery electrolytes, sell to different customers and never compete. Conversely, a neighborhood café and a supermarket with a ready-meals aisle may fight for the same customer’s lunch while sitting in different groups. Substitutes cross group lines. The remedy is to move up or down a tier, or to build your own peer set.
2. Multi-product companies. With one box per company, a division can compete with firms in a different sector from its parent. Picture a consumer electronics maker whose payments division earns most of its profit: the label says electronics, but that division’s rivals are banks and card networks filed under financials.
3. Geography. Global groupings suit global industries, such as manufactured goods and digital products. They suit local services poorly. Dental clinics, driving schools and home-care agencies compete town by town, because customers will not travel far and licensing is often national, so a chain in one country has little in common with one abroad. Industries can also change: private tutoring was once local, and online lessons have made much of it a global market.
4. Changes over time. Providers create and rename groups. Real estate was carved out of financials into a sector of its own, which breaks long-run sector statistics. Listings and delistings change the constituents and add survivorship bias to historical results. Restate history to the latest groups, and build survivorship-free datasets where possible.

What other ways are there to group companies?

Industry is not the only way to group companies. Outside industry analysis, such as in index construction and performance evaluation, other groupings are common.

Grouping methods besides industryused in index construction and performance evaluation

• Business cycle sensitivity Memorize cyclical or defensive, usually by whole sector
• Statistical similarities Use it clusters of ratios, returns or size
  • Valuation, growth, profitability ratios and market capitalization
  • Price behavior volatility, momentum, return co-movement
• Geography Use it by country, then developed, emerging or frontier
  • Country set by incorporation, primary listing, headquarters, market perception
  • Not set by where revenue is earned
• ESG characteristics Know the idea carbon intensity, board diversity, exposure to tobacco or gambling

Business cycle sensitivity. Cyclical companies have sales, profits and valuations that move strongly with broad economic activity (gross domestic product, GDP). Defensive companies are much less affected. The split is normally made by whole sector: financials, basic materials, consumer discretionary, industrials and energy are cyclical; consumer staples, health care and utilities are defensive. It can be combined with other methods, for example by country, because countries sit at different points in the cycle.

Statistical similarities. Statistical similarities means clustering companies by financial ratios or by how their security prices move together. Groups can be built on valuation ratios, growth, profitability, size by market capitalization, or price behavior such as volatility and momentum. These groups are usually relative (for example, companies at or above the 75th percentile of dividend yield) and turn over a lot, because rankings change. They can lack economic logic.

Geography. Companies are assigned a country, then countries are collected into developed, emerging and frontier markets . The country is normally where the issuer is incorporated, where its main listing is, where its headquarters sits, or what the market perceives. The mix of revenue by region is generally not used, even though it may matter most to the analyst. A company incorporated, listed and headquartered in Korea that earns most of its sales in Europe is still a Korean company. The developed, emerging or frontier label is a judgment, not a formula. Providers weigh the size and liquidity of the equity market, income per person and restrictions on foreign investment.

Environmental, social and governance (ESG) characteristics. Companies can also be grouped by measures such as carbon emissions relative to revenue, board diversity or exposure to businesses such as tobacco and gambling, then combined into scores.

Go deeper Why defensive does not mean immune

A severe downturn hurts almost every company, so the difference between cyclical and defensive is a matter of degree. Companies at different stages inside one industry can also differ: a young firm with a new technology may keep growing in a cyclical industry that is shrinking overall. Treat the label as a good first guess about sensitivity, and check how the business model works: whether purchases can be postponed, how much debt the customers carry and how much pricing power the company has.

Go deeper Technology and real estate: cyclical or defensive?

The ten-sector exercise in the 2026 curriculum text sorts consumer staples, health care, utilities, technology and real estate as defensive, and consumer discretionary, energy, financials, industrials and materials as cyclical. Memorize the three core defensive sectors (staples, health care, utilities) with confidence. If a question gives only a technology or real estate sector to sort, expect the curriculum’s treatment, but notice that the rule is always sensitivity to GDP, not the sector’s name.

Go deeper Why classification matters beyond research

Index providers use the same schemes to build sector indexes, and funds and benchmarks follow those indexes, so a company’s classification affects which sector funds hold it and what weight it carries. Performance attribution also reports results by sector using these groups.