{
  "title": "Your 30-Year Plan Is Built on a 7-Year Forecast: What the Horizon Mismatch Costs (2026)",
  "canonical": "https://quantcalc.app/research/cma-horizon-mismatch-2026/",
  "version": "2026.1",
  "license": "CC-BY-4.0",
  "license_url": "https://creativecommons.org/licenses/by/4.0/",
  "date_published": "2026-09-18",
  "date_modified": "2026-09-18",
  "engine": "QuantCalc production /api/simulate",
  "generated_utc": "2026-09-16T00:00:00+00:00",
  "provenance": "Snapshot for gen_horizon_mismatch_study.mjs. Produced by running the PRODUCTION engine via /api/simulate on 2026-09-16 with a short-dated PRO key that was revoked immediately afterwards. Render-only generator: the run is not reproducible from this repo without an engine and a licence, so the numbers are committed rather than recomputed at build time.",
  "plan": {
    "starting_balance": 1000000,
    "allocation": {
      "us_equity": 0.45,
      "intl_equity": 0.15,
      "bonds": 0.4
    },
    "initial_withdrawal": 40000,
    "withdrawal_indexing": 0.025,
    "current_age": 65,
    "end_age": 95,
    "horizon_years": 30,
    "paths_per_arm": 10000,
    "seed": 42,
    "volatility_and_correlations": "J.P. Morgan published values, held constant across every arm so only the return path differs"
  },
  "long_run_anchor": {
    "id": "jpmorgan",
    "name": "J.P. Morgan",
    "horizon_years": 30,
    "success_rate": 87.1,
    "median_terminal": 770469.0025365973,
    "source": "https://am.jpmorgan.com/us/en/asset-management/adv/insights/portfolio-insights/ltcma/",
    "source_citation": "https://am.jpmorgan.com/us/en/asset-management/adv/insights/portfolio-insights/ltcma/ (checked 2026-09-16)"
  },
  "arms": [
    {
      "id": "gmo",
      "name": "GMO",
      "published_horizon_years": 7,
      "stretched_to_30y": {
        "success_rate": 5,
        "median_terminal": 0
      },
      "own_horizon_then_anchor": {
        "success_rate": 45.7,
        "median_terminal": 0
      },
      "success_rate_gap_points": 40.7,
      "source": "https://www.gmo.com/americas/research-library/gmo-7-year-asset-class-forecast-4q-2025_gmo7yearassetclassforecast/",
      "source_as_run": "https://www.gmo.com/americas/research-library/gmo-7-year-asset-class-forecast-4q-2025_gmo7yearassetclassforecast/",
      "source_citation": "https://www.gmo.com/americas/research-library/gmo-7-year-asset-class-forecast-4q-2025_gmo7yearassetclassforecast/ (checked 2026-09-16)"
    },
    {
      "id": "vanguard",
      "name": "Vanguard",
      "published_horizon_years": 10,
      "stretched_to_30y": {
        "success_rate": 68.8,
        "median_terminal": 255421.28
      },
      "own_horizon_then_anchor": {
        "success_rate": 76,
        "median_terminal": 486419.16
      },
      "success_rate_gap_points": 7.2,
      "source": "https://corporate.vanguard.com/content/corporatesite/us/en/corp/vemo/vanguard-economic-market-outlook.html",
      "source_as_run": "https://corporate.vanguard.com/content/corporatesite/us/en/corp/vemo/vanguard-economic-market-outlook.html",
      "source_citation": "https://corporate.vanguard.com/content/corporatesite/us/en/corp/vemo/vanguard-economic-market-outlook.html (checked 2026-09-16)"
    },
    {
      "id": "blackrock",
      "name": "BlackRock",
      "published_horizon_years": 10,
      "stretched_to_30y": {
        "success_rate": 74.9,
        "median_terminal": 374168.04
      },
      "own_horizon_then_anchor": {
        "success_rate": 80.7,
        "median_terminal": 552814.33
      },
      "success_rate_gap_points": 5.8,
      "source": "https://www.morningstar.com/markets/experts-forecast-stock-bond-returns-2026-edition",
      "source_as_run": "https://www.morningstar.com/markets/experts-forecast-stock-bond-returns-2026-edition",
      "source_citation": "https://www.morningstar.com/markets/experts-forecast-stock-bond-returns-2026-edition (checked 2026-09-16)"
    },
    {
      "id": "invesco",
      "name": "Invesco",
      "published_horizon_years": 10,
      "stretched_to_30y": {
        "success_rate": 76,
        "median_terminal": 398880.6
      },
      "own_horizon_then_anchor": {
        "success_rate": 81.1,
        "median_terminal": 567562.75
      },
      "success_rate_gap_points": 5.1,
      "source": "https://www.invesco.com/us/en/insights/long-term-capital-market-assumptions-outlook.html",
      "source_as_run": "https://www.invesco.com/us/en/insights/long-term-capital-market-assumptions-outlook.html",
      "source_citation": "https://www.invesco.com/us/en/insights/long-term-capital-market-assumptions-outlook.html (checked 2026-09-16)"
    },
    {
      "id": "schwab",
      "name": "Charles Schwab",
      "published_horizon_years": 20,
      "stretched_to_30y": {
        "success_rate": 82.3,
        "median_terminal": 573135.82
      },
      "own_horizon_then_anchor": {
        "success_rate": 82.6,
        "median_terminal": 607646.72
      },
      "success_rate_gap_points": 0.4,
      "source": "https://www.schwab.com/learn/story/schwabs-long-term-capital-market-expectations",
      "source_as_run": "https://www.schwab.com/learn/story/schwabs-long-term-capital-market-expectations",
      "source_citation": "https://www.schwab.com/learn/story/schwabs-long-term-capital-market-expectations (checked 2026-09-16)"
    }
  ]
}