How to Find a Stock's Sector and Industry

The most common system for classifying stocks worldwide sorts companies into 163 sub-industries, which roll up into just 11 sectors. It assigns each company a single slot based on its main business, which is why a company you'd call "tech" can land in Communication Services or Financials.

Watch it play out163 sub-industries collapse into 11 sectors

GICS, the most common system for classifying stocks worldwide, sorts companies into 163 sub-industries.

Those roll up into 74 industries...

...then 25 industry groups...

...and just 11 sectors. Each company gets a single slot, based on its main business, not its branding.

That is why a company you'd call "tech" can land in Communication Services or Financials.

Replay

To find a stock's sector, look it up under a named classification system, usually GICS, from the index provider or a licensed data feed. Then check the label against the company's annual report. A worked example below shows how a company can earn 70% of its profit from a business its sector label doesn't mention.

Watch it play outThe label follows revenue; the profit can live elsewhere

A hypothetical company with two segments. Cut its $10 billion of revenue into 100 dots.

Software brings in 40% of revenue, equipment 60%. Revenue points to industrial equipment, so that's the likely label.

Now count the $2.0 billion of operating profit instead. Software earns 70% of it.

Value it only against industrial-equipment peers and you benchmark the smaller part of its earnings.

Replay

The short version

• GICS, the Global Industry Classification Standard, was built by S&P Dow Jones Indices and MSCI. It has four levels: 11 sectors, 25 industry groups, 74 industries and 163 sub-industries.
• A company's slot depends mainly on where its revenue comes from, with earnings and market perception also considered. Branding and who the customers are don't decide it.
• Websites disagree because they use different systems, update on different dates, or point to a different share class.

Sector vs. industry

A sector is the broadest bucket. An industry is narrower. GICS stacks four levels:

Four levels, from 11 sectors down to 163 sub-industries

1. SectorThe broadest bucket11
2. Industry group25
3. Industry74
4. Sub-industryEach company gets exactly one163

The sub-industry decides every level above it

Each company gets one sub-industry, and that decides everything above it. The figures come from S&P's current GICS overview; the rules are in the GICS methodology.

The 11 sectors are:

• Communication Services
• Consumer Discretionary
• Consumer Staples
• Energy
• Financials
• Health Care
• Industrials
• Information Technology
• Materials
• Real Estate
• Utilities

These are broad. Two Information Technology companies can have very different customers, margins, cyclicality, capital needs and sensitivity to interest rates. The sector is where peer selection starts, not where it ends.

Check the claimThree beliefs about sector labels

ClaimA company's branding tells you its sector.Tap to checkMythGICS classifies by principal business activity, mainly revenue. Branding and who the customers are don't decide it.Flip backClaimTwo companies in the same sector make natural peers.Tap to checkMythTwo Information Technology companies can differ in customers, margins, cyclicality, capital needs and rate sensitivity. Go below the sector.Flip backClaimHolding stocks from three sectors keeps you diversified.Tap to checkPartly trueNot if they share a driver. In the example below, three sectors put 40% of a portfolio on one AI-capex cycle.Flip back

How to look up a stock's sector in five steps

1. Pin down the exact security. Confirm the legal company name, ticker, exchange and share class. Similar tickers, renamed companies and multiple share classes cause easy mistakes.
2. Name the classification system. Check whether the source uses GICS, the Industry Classification Benchmark, NAICS, SIC, or its own in-house scheme. Two providers can disagree and both be consistent with their own rules.
3. Check the index provider. If the company is in an S&P or MSCI index, the provider or a licensed data feed may show its classification. Note the effective date, because classifications change.
4. Read what the company actually does. The latest annual report shows revenue by segment, operating profit, assets and management's description. Find filings through EDGAR company search.
5. Go below the sector. Record the industry group, industry and sub-industry. A sector-level comparison can hide the real peer set.

Five checks before you trust a sector label

1. Security (Ticker, share class) to System (GICS, NAICS, SIC)
2. System (GICS, NAICS, SIC) to Provider (Effective date)
3. Provider (Effective date) to Filing (Segment revenue)
4. Filing (Segment revenue) to Drill down (All four levels)

Why do websites show different sectors?

Classification systems have different structures and rules, and data vendors update on different schedules. Some map their own categories onto GICS-style labels.

Three common systems, built for different jobs

GICSS&P Dow Jones Indices and MSCI

• Built by index providers for investing
• Four levels, down to 163 sub-industries

Use for index and benchmark questions

NAICSGovernment industry codes

• Separate hierarchy and rules from GICS

SICGovernment industry codes

• Separate hierarchy and rules from GICS
• EDGAR lists an SIC code for each filer

Common causes of disagreement:

• One source uses GICS and another uses its own taxonomy
• A merger, sale or spin-off changed the business mix
• One provider hasn't processed a classification update yet
• The ticker points to a different security or share class
• A conglomerate has no perfect single category
• The website mixes up sector, industry and business description

Don't settle it by picking whichever label shows up most often. Find the methodology and the effective date behind each one.

Three shortcuts that mislead

Member research: Companies in different sub-industries can live off the same buildout. Issue 06 compares five companies in AI's optical supply chain on yields, reliability, cash conversion and valuation to work out who keeps the profits.

What about companies with several big businesses?

GICS still gives them one primary classification, based on principal business activity: mainly revenue, with earnings and market perception also weighed.

For research, keep the official label and add a segment-by-segment view. The assigned sector matters for index membership. The earnings drivers may need comparisons with peers from several industries.

Worked example: the label follows revenue, the value follows profit

Hypothetical example: a company reports two segments in its annual report.

Revenue points to industrial equipment, so that's the likely primary classification, though earnings and market perception are also weighed. Yet 70% of the profit comes from software. If you value this company only against industrial-equipment peers, you're benchmarking the smaller part of its earnings. The fix is to compare each segment with its own peers, then add them up.

Software is 40% of revenue but 70% of profit

Share of revenueShare of operating profit

255075%0

60%30%

Industrial equipmentShare of revenue60%Share of operating profit30%

40%70%

SoftwareShare of revenue40%Share of operating profit70%

Industrial equipmentSoftware

How the sector label helps your research

• Peer comparisons. Valuation ratios mean more when peers share economics. Compare business models, margins, growth, capital intensity and balance sheets before leaning on sector membership. Yield Theory's stock comparison directory limits comparisons to source-backed companies in the same broad sector and shows the SEC filing evidence behind each pair.
• Portfolio concentration. Sector weights show one kind of concentration, but hidden overlaps remain, so diversification by sector can overstate how spread out you are. A data-center utility, a chip company and an industrial equipment supplier may all depend on the same AI-capex cycle (capex being the money companies spend on long-lived assets like data centers).
• Economic sensitivity. Sectors help you organize exposure to rates, commodities, credit, consumer demand and regulation. They don't guarantee every member behaves the same way.
• Benchmark analysis. Use the benchmark's own classification when explaining sector over- or underweights. Mixing systems can create false ones.

The same caution applies to market labels like cyclical stocks and defensive stocks: check the operating traits instead of assuming the sector name decides behavior.

Worked example: three sectors, one bet

Hypothetical example: a $100,000 portfolio holds 15% in a data-center utility, 15% in a chip company and 10% in an industrial equipment supplier. That's three different sectors, but 40% of the portfolio rides the same AI-capex cycle. Suppose that cycle turns:

Make a guess

The chip company falls 40%, the utility and equipment supplier 25%, and everything else 8%. How much does the whole $100,000 portfolio lose?

Tap your guess

0–5%Your guess5–10%Your guess10–15%Your guess15–20%Your guessOver 20%Your guess

01234567890123456789.01234567890123456789%Portfolio loss

Spot on.Close, a little low.Close, a little high.Way off, too low.Way off, too high. It was 17.05%.

17.05%, or $17,050. The two AI-capex positions alone cost 12.25 points, even though a sector chart would call the portfolio well spread.

Portfolio loss17.05%

Chip company6.0%

Utility and equipment supplier6.25%

Everything else4.8%

A sector pie chart would have shown this portfolio as well spread. The shared driver is what does the damage.

Try it yourself

A 10-minute exercise with a stock you own or follow:

1. Open its stock page on the site, for example /stocks/NVDA, and write down the sector and industry it lists.
2. Find its latest annual report through EDGAR company search. In the segment note, record each segment's share of revenue and of operating profit, as in the first worked example.
3. Check whether the largest revenue segment matches the label, and whether the largest profit segment does too.
4. Pick a candidate peer in the stock comparison directory and check whether its segment mix actually resembles your company's.
5. Enter your largest position and your total exposure to its main economic driver in the portfolio concentration stress test.

You should now be able to answer: who are this stock's real peers, and how much of your portfolio shares its main driver?

Our read

Finding a stock's sector takes a minute. Using it well takes more care. Keep the official GICS label for index and benchmark questions, but pick peers from the company's segments and economic drivers.

Revisit the label when:

• Revenue mix shifts between segments in the annual report
• A merger, sale or spin-off closes
• The provider publishes a new effective date or structure change

Before choosing peers, write down the security, the system and provider, all four GICS levels with the date, revenue and profit by segment, major customers and end markets, and what the official label might hide. To turn that into a research question, the course's free opening lesson, Think like an owner, shows how to turn a stock story into a testable business question.

Questions readers ask

Can a company's sector change?

Yes. A merger, sale or spin-off can shift the business mix, and providers can revise both their structures and individual assignments. That's why you should record the effective date next to any classification.

Why isn't a company I think of as "tech" in Information Technology?

GICS classifies by principal business activity, mainly revenue, not by branding. Some software-like platforms land in Communication Services or Financials because their revenue model and customers fit there.

What's the difference between GICS, NAICS and SIC?

They're separate taxonomies with different hierarchies and rules. GICS was built by index providers for investing. NAICS and SIC are government industry codes, and EDGAR lists an SIC code for each filer. Always name which system a label comes from.

Should I only compare a stock with others in its sector?

Start there, then narrow to the same sub-industry and, above all, to companies with similar economics. As the segment example shows, a company's biggest profit driver may sit outside its assigned sector.

Go deeper with member research

Sector labels are a starting point, not the story. This member case study looks at an industrials company whose growth runs through AI data-center construction:

• Comfort Systems and the scarce capacity behind AI construction: Whether the backlog and cash conversion looked investable on February 20, 2026, and what the later gains really rewarded.
• The fundamental research course: 40 chapters that take you from reading a 10-K to writing your own research memo. The first chapter is free.

Limits of this data

• Classification providers can revise their structures and company assignments, so the 11/25/74/163 counts and any single company's slot can change. Check current methodology and constituent data.