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S&P 500 Fundamental vs. Market-Cap Concentration

The Top 10 Issuers Carry 40.45% of Market Weight, but the Top 10 Capex Contributors Carry Only 19.89%
By Lee BaileyPublished September 22, 2026Data snapshot September 21, 2026Version 1.0500 matched issuers
Fundamentals vs. market weight

Market concentration broadly tracks the leading revenue and profit cohorts, but capital spending is a different story.

The ten largest S&P 500 issuers carry 40.45% of normalized market weight. But the central comparison holds the company cohort constant: the ten largest covered revenue contributors generate 26.32% of covered positive revenue and carry 24.97% of market weight, while the ten largest capex contributors generate 50.68% of covered capex and carry only 19.89%.

40.45%overall top-10 issuer market weight
The top 20 issuers carry 50.53%.
-0.53 pptop-10 net-income cohort gap
37.89% of covered positive net income versus 37.36% market weight.
-30.79 pptop-10 capex cohort gap
50.68% of covered capex versus 19.89% market weight.
A same-cohort gap is market weight minus fundamental share. It is descriptive, not a claim that the cohort is overvalued, undervalued, efficient, inefficient, high quality, or low quality.

Revenue and net income are close at the top 10; capex is not

The comparison below uses the exact companies that rank in the top 10 for each fundamental. That is different from comparing every fundamental with the overall market's ten largest companies.

FundamentalCoverageTop-10 fundamental shareSame-cohort market weightMarket minus fundamental
Revenue468/500 (93.6%)26.32%24.97%-1.35 pp
Operating income384/500 (76.8%)39.55%36.88%-2.67 pp
Net income457/500 (91.4%)37.89%37.36%-0.53 pp
Operating cash flow489/500 (97.8%)31.03%36.37%+5.34 pp
Free cash flow325/500 (65.0%)31.32%27.24%-4.08 pp
Capital expenditures331/500 (66.2%)50.68%19.89%-30.79 pp

Explore the six same-cohort comparisons

Switch between top 10 and top 20 cohorts to see the exact contributors, company-level share gaps, sector gaps, and metric coverage. Overall market top-10 and top-20 weights remain visible for context but are not substituted for the same-cohort denominator.

26.32%fundamental shareof the covered positive-value pool
24.97%same-cohort market weightnormalized issuer weight
-1.35 ppmarket minus fundamentaldescriptive same-cohort gap
468/500fundamental coverage93.6% of issuers
Overall market top 10: 40.45%Overall market top 20: 50.53%

Same-cohort company detail

10 issuers
  1. #1 AMZNAmazon · Consumer Discretionary
    4.21% fundamental3.79% market · -0.42 pp
  2. #2 WMTWalmart · Consumer Staples
    4.15% fundamental0.72% market · -3.43 pp
  3. #3 UNHUnitedHealth Group · Health Care
    2.63% fundamental0.51% market · -2.12 pp
  4. #4 AAPLApple Inc. · Information Technology
    2.44% fundamental7.39% market · +4.95 pp
  5. #5 MCKMcKesson Corporation · Health Care
    2.37% fundamental0.15% market · -2.22 pp
  6. #6 GOOG/GOOGLAlphabet Inc. · Communication Services
    2.37% fundamental5.61% market · +3.24 pp
  7. #7 CVSCVS Health · Health Care
    2.36% fundamental0.17% market · -2.19 pp
  8. #8 XOMExxonMobil · Energy
    1.95% fundamental0.97% market · -0.98 pp
  9. #9 MSFTMicrosoft · Information Technology
    1.95% fundamental5.57% market · +3.62 pp
  10. #10 CORCencora · Health Care
    1.89% fundamental0.09% market · -1.80 pp

Largest sector gaps

Absolute gap order
  1. Information Technology13.59% fundamental
    39.04% market+25.45 pp
  2. Health Care21.40% fundamental
    9.16% market-12.24 pp
  3. Consumer Staples11.64% fundamental
    4.36% market-7.28 pp
  4. Consumer Discretionary12.34% fundamental
    8.77% market-3.57 pp
  5. Energy6.32% fundamental
    3.38% market-2.94 pp
  6. Industrials10.15% fundamental
    8.07% market-2.08 pp

Coverage changes how much weight to put on each comparison

Revenue, net income, and operating cash flow cover most of the 500-issuer universe. Free cash flow and capex do not. A large gap in a partial pool can be economically interesting without being a full-index statement.

Broad coverage

Revenue covers 93.6% of issuers, net income 91.4%, and operating cash flow 97.8%.

Partial coverage

Free cash flow covers 65.0% and capital expenditures cover 66.2%. Those gaps describe the covered positive-value pools, not all 500 issuers.

Methodology and interpretation boundaries

Market denominator

Market weights use the September 21, 2026 IVV equity market values for the exact frozen 503 S&P 500 security lines, renormalized to 100% and aggregated to 500 issuer CIKs.

Same-cohort rule

For each fundamental, Grizzly Bulls takes the exact reviewed top 10 or top 20 positive contributors from the Fundamental Concentration Atlas and compares their share of that covered positive-value pool with the market weight carried by those same issuers.

Coverage

Fundamental coverage remains metric-specific. Revenue and operating cash flow are broad, while free cash flow and capital expenditures cover materially smaller issuer sets.

Interpretation

A positive gap means the same cohort carries more market weight than its share of the covered fundamental pool. A negative gap means it generates more of the covered fundamental than its market weight. Neither direction is a valuation, quality, efficiency, or recommendation judgment.

The market-weight proxy comes from iShares Core S&P 500 ETF holdings ↗. Fundamental cohorts come from the reviewed S&P 500 Fundamental Concentration Atlas. This page uses the frozen reviewed dataset and does not fetch live holdings at page render or rebuild the join.

Download the comparison

Research data

Public study files are available for verification and analysis. The Grizzly Bulls Data License covers these public downloads; third-party source records retain their own rights. Reuse terms →
  • CSVComparison summary CSV
    Six reviewed metric rows with coverage, top-10/top-20 fundamental shares, same-cohort market weights, and percentage-point gaps.
    Data snapshot September 21, 2026 · Reuse with attribution to the canonical study.
    Download CSV
  • JSONComparison JSON
    Structured derived comparison data including market concentration, public company and sector cohorts, selected findings, and methodology boundaries. Raw IVV holdings and internal review metadata are not included.
    Data snapshot September 21, 2026 · Reuse with attribution to the canonical study.
    Download JSON

Citation and reuse

Lee Bailey. “S&P 500 Fundamental vs. Market-Cap Concentration: The Top 10 Issuers Carry 40.45% of Market Weight, but the Top 10 Capex Contributors Carry Only 19.89%.” Grizzly Bulls, September 22, 2026. Version 1.0. Data snapshot September 21, 2026. https://grizzlybulls.com/research/sp500-fundamental-vs-market-cap-concentration

When citing a same-cohort gap, preserve the metric's coverage denominator and the September 21, 2026 data date. For methodology questions or corrections, contact Grizzly Bulls research.