{
  "title": "S&P 500 AI Concentration: How Much of the Index Is AI-Linked?",
  "version": "1.0",
  "dataAsOf": "2026-09-09",
  "snapshot": {
    "topTenSecurityLinesWeightPct": 38.09,
    "topTenSecurityLinesUniqueCompanies": 9,
    "informationTechnologySectorWeightPct": 38.28,
    "topSecurityLines": [
      { "symbol": "NVDA", "name": "NVIDIA Corporation", "weightPct": 8.25 },
      { "symbol": "AAPL", "name": "Apple Inc.", "weightPct": 7.05 },
      { "symbol": "MSFT", "name": "Microsoft Corporation", "weightPct": 5.56 },
      { "symbol": "AMZN", "name": "Amazon.com Inc.", "weightPct": 3.76 },
      { "symbol": "GOOGL", "name": "Alphabet Inc. Class A", "weightPct": 2.95 },
      { "symbol": "AVGO", "name": "Broadcom Inc.", "weightPct": 2.63 },
      { "symbol": "GOOG", "name": "Alphabet Inc. Class C", "weightPct": 2.36 },
      { "symbol": "META", "name": "Meta Platforms Inc. Class A", "weightPct": 2.19 },
      { "symbol": "MU", "name": "Micron Technology Inc.", "weightPct": 1.76 },
      { "symbol": "TSLA", "name": "Tesla Inc.", "weightPct": 1.58 }
    ]
  },
  "conservativeAiLinkedCohort": {
    "definition": "Top-weight companies with direct current primary-source evidence that a material part of the business or capital-spending cycle is tied to AI infrastructure supply or large-scale AI/cloud platform infrastructure.",
    "infrastructureSuppliersWeightPct": 12.64,
    "platformsAndInfrastructureBuyersWeightPct": 16.82,
    "combinedUniqueCompanies": 7,
    "combinedSecurityLines": 8,
    "combinedWeightPct": 29.46,
    "shareOfTopTenSecurityLineWeightPct": 77.34313468101865,
    "excludedTopTen": [
      {
        "company": "Apple",
        "weightPct": 7.05,
        "reason": "Apple has a material AI strategy, but the reviewed current financial disclosure does not separately quantify an AI revenue or infrastructure-spending channel comparable to the conservative cohort."
      },
      {
        "company": "Tesla",
        "weightPct": 1.58,
        "reason": "Tesla explicitly describes AI initiatives and AI-driven capital spending, but its current AI economics are embedded in automotive, robotics and energy rather than the common data-center/cloud supplier-platform cycle used for this cohort."
      }
    ],
    "interpretationBoundary": "This is a conservative company-level exposure screen. It is not an estimate of the fraction of S&P 500 revenue, earnings, cash flow or valuation attributable to AI."
  },
  "historicalComparison": {
    "june1965TopTenWeightPct": 38.24,
    "june1965TopTen": [
      { "company": "AT&T", "weightPct": 9.11 },
      { "company": "General Motors", "weightPct": 7.06 },
      { "company": "Standard Oil of New Jersey (Exxon)", "weightPct": 4.36 },
      { "company": "IBM", "weightPct": 4.15 },
      { "company": "Du Pont", "weightPct": 2.8 },
      { "company": "Texaco", "weightPct": 2.71 },
      { "company": "Sears, Roebuck", "weightPct": 2.68 },
      { "company": "General Electric", "weightPct": 2.24 },
      { "company": "Eastman Kodak", "weightPct": 1.66 },
      { "company": "Gulf Oil (Chevron)", "weightPct": 1.47 }
    ]
  },
  "sources": {
    "sp500Methodology": "https://www.spglobal.com/spdji/en/methodology/article/sp-us-indices-methodology/",
    "officialSp500": "https://www.spglobal.com/spdji/en/indices/equity/sp-500/",
    "stateStreetHoldings": "https://www.ssga.com/us/en/intermediary/etfs/state-street-spdr-sp-500-etf-trust-spy",
    "historicalConcentrationStudy": "https://www.spglobal.com/spdji/en/documents/research/research-in-the-shadows-of-giants.pdf"
  }
}