{
  "title": "S&P 500 Earnings Concentration: Are the Top 10 Backed by Profits?",
  "path": "/research/sp500-earnings-concentration",
  "publishedAt": "2026-09-20",
  "updatedAt": null,
  "dataAsOf": "2026-03-31",
  "version": "1.0",
  "snapshots": [
    {
      "date": "2024-03-31",
      "topTenMarketCapSharePct": 33.5,
      "topTenTrailingEarningsSharePct": 25.5,
      "capMinusEarningsGapPctPoints": 8,
      "earningsShareAsPctOfMarketCapShare": 76.1
    },
    {
      "date": "2026-03-31",
      "topTenMarketCapSharePct": 37.9,
      "topTenTrailingEarningsSharePct": 33.2,
      "capMinusEarningsGapPctPoints": 4.7,
      "earningsShareAsPctOfMarketCapShare": 87.6
    }
  ],
  "selectedFindings": {
    "marketCapShareIncreasePctPoints": 4.4,
    "earningsShareIncreasePctPoints": 7.7,
    "gap2024PctPoints": 8,
    "gap2026PctPoints": 4.7,
    "gapNarrowingPctPoints": 3.3,
    "earningsCoverage2024Pct": 76.1,
    "earningsCoverage2026Pct": 87.6,
    "earningsCoverageIncreasePctPoints": 11.5
  },
  "sources": {
    "march2024Guide": "https://img1.wsimg.com/blobby/go/132cbe13-cc82-44df-8127-b12f8a7d6c1c/JP%20Morgan%20-%20Q2%202024%20Guide%20to%20the%20Markets.pdf",
    "march2026Guide": "https://am.jpmorgan.com/content/dam/jpm-am-aem/global/en/insights/market-insights/guide-to-the-markets/mi-guide-to-the-markets-us.pdf"
  },
  "methodology": {
    "cohortRule": "The source defines the top 10 from the 10 largest S&P 500 index companies at the beginning of each month.",
    "frequencyBoundary": "The reviewed source charts begin in 1996, but this public dataset contains only the two exact labeled March snapshots rather than digitized monthly chart values.",
    "earningsBoundary": "Earnings concentration is the source-reported share of S&P 500 last-12-month earnings generated by the top 10 companies under the source methodology.",
    "inferenceBoundary": "The comparison measures how much index market-cap concentration was accompanied by trailing earnings concentration at two dates. It does not establish that the top 10 were fairly valued or predict subsequent returns."
  }
}