{
  "page": "compare",
  "query": {
    "a": "MBB",
    "b": "VFIIX"
  },
  "retrieved_at": "2026-07-07T19:12:41+00:00",
  "disclaimer": "Informational only — not investment advice. FundWatcher presents publicly available data and makes no recommendation to buy or sell any security. Verify all figures against the source filing before relying on them.",
  "attribution": "Data sourced from U.S. SEC EDGAR filings (Forms N-PORT, N-CEN, and prospectus Risk/Return summaries). FundWatcher is not affiliated with the SEC.",
  "terms": {
    "notice": "Use of this data is subject to the FundWatcher Terms of Service. Information may be used only for personal, non-commercial research and may not be redistributed.",
    "url": "https://fundwatcher.app/terms/"
  },
  "fund_a": {
    "name": "iShares MBS ETF",
    "ticker": "MBB",
    "slug": "MBB",
    "series_id": "S000013702",
    "html_url": "https://fundwatcher.app/funds/MBB/"
  },
  "fund_b": {
    "name": "VANGUARD GNMA FUND",
    "ticker": "VFIIX",
    "slug": "VFIIX",
    "series_id": "S000002582",
    "html_url": "https://fundwatcher.app/funds/VFIIX/"
  },
  "overlap": {
    "coverage_a_by_b": "0.07029143050373048180430190503",
    "coverage_b_by_a": "0.07029143050373048180430190502",
    "shared_count": 539,
    "as_of": {
      "a": "2026-02-28",
      "b": "2026-01-31"
    },
    "a_top": [
      {
        "name": "BlackRock Cash Funds: Treasury, SL Agency Shares",
        "value": "2349848882.32",
        "weight": "0.05655290",
        "shared": false
      },
      {
        "name": "FR SD8146",
        "value": "427589929.06",
        "weight": "0.01029064",
        "shared": false
      },
      {
        "name": "GNII II 5.5% 03/01/2056 #TBA",
        "value": "399517163.25",
        "weight": "0.00961502",
        "shared": true
      },
      {
        "name": "FNCL 5 3/24",
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      },
      {
        "name": "G2 MA7648",
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      },
      {
        "name": "G2 MA7766",
        "value": "217494998.47",
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      },
      {
        "name": "FN MA4492",
        "value": "212474536.60",
        "weight": "0.00511354",
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      },
      {
        "name": "G2SF 5 3/25",
        "value": "209896727.56",
        "weight": "0.00505150",
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      },
      {
        "name": "FR SD8140",
        "value": "204523050.63",
        "weight": "0.00492218",
        "shared": false
      },
      {
        "name": "FNCL 5.5 3/25",
        "value": "197749445.88",
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      },
      {
        "name": "G2 MA7472",
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      },
      {
        "name": "Government National Mortgage Association, TBA",
        "value": "181046291.07",
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      },
      {
        "name": "FN MA4465",
        "value": "180370505.38",
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      },
      {
        "name": "Uniform Mortgage-Backed Securities",
        "value": "178332612.01",
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      },
      {
        "name": "G2 MB0025",
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      },
      {
        "name": "G2 MA7935",
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      },
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        "name": "G2 MA7367",
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      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "140022705.46",
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      },
      {
        "name": "FR SD8199",
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      },
      {
        "name": "FN MA4281",
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        "weight": "0.00320581",
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      },
      {
        "name": "Fannie Mae Pool",
        "value": "133096404.12",
        "weight": "0.00320318",
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      },
      {
        "name": "G2 MA9171",
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      {
        "name": "FN MA4437",
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      {
        "name": "G2 MA7826",
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        "name": "G2 MA7534",
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      {
        "name": "FN MA4305",
        "value": "120559723.67",
        "weight": "0.00290146",
        "shared": false
      },
      {
        "name": "Fannie Mae Pool",
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        "weight": "0.00278257",
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      },
      {
        "name": "G2 MA7936",
        "value": "115515880.49",
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      },
      {
        "name": "G2 MA7051",
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      {
        "name": "G2 MA7767",
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      {
        "name": "G2 MA9965",
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      {
        "name": "FR SD8324",
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      },
      {
        "name": "FNCL 6 3/24",
        "value": "101312358.87",
        "weight": "0.00243825",
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      },
      {
        "name": "G2 MB0624",
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      },
      {
        "name": "FR SD8182",
        "value": "96947222.98",
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      },
      {
        "name": "FANNIE MAE POOL FN 05/52 FIXED VAR",
        "value": "93078582.60",
        "weight": "0.00224009",
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      },
      {
        "name": "G2 MA9781",
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      {
        "name": "G2 MA7987",
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      {
        "name": "G2 MA7589",
        "value": "91465086.29",
        "weight": "0.00220125",
        "shared": true
      },
      {
        "name": "FR SD8134",
        "value": "90692946.45",
        "weight": "0.00218267",
        "shared": false
      },
      {
        "name": "FR SD8362",
        "value": "90321930.34",
        "weight": "0.00217374",
        "shared": false
      },
      {
        "name": "Uniform Mortgage-Backed Securities",
        "value": "87655418.50",
        "weight": "0.00210957",
        "shared": false
      },
      {
        "name": "Uniform Mortgage-Backed Securities",
        "value": "87111954.59",
        "weight": "0.00209649",
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      },
      {
        "name": "FR RA5205",
        "value": "87091149.17",
        "weight": "0.00209599",
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      },
      {
        "name": "FNCL UMBS 3.0 CA9308 02-01-51",
        "value": "85646847.71",
        "weight": "0.00206123",
        "shared": false
      },
      {
        "name": "G2 MA9852",
        "value": "84798764.06",
        "weight": "0.00204082",
        "shared": true
      },
      {
        "name": "Uniform Mortgage-Backed Securities",
        "value": "82184209.52",
        "weight": "0.00197790",
        "shared": false
      },
      {
        "name": "G2 MB0091",
        "value": "80607537.41",
        "weight": "0.00193995",
        "shared": false
      },
      {
        "name": "Freddie Mac Pool",
        "value": "79799967.76",
        "weight": "0.00192051",
        "shared": false
      },
      {
        "name": "FR SD8234",
        "value": "77789632.23",
        "weight": "0.00187213",
        "shared": false
      }
    ],
    "b_top": [
      {
        "name": "G2SF 5 3/25",
        "value": "467547656.85",
        "weight": "0.03567772",
        "shared": true
      },
      {
        "name": "TBA GNMA 30 YR 5.50000000",
        "value": "463821269.70",
        "weight": "0.03539336",
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      },
      {
        "name": "G2 MA6994",
        "value": "436204870.39",
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      },
      {
        "name": "Government National Mortgage Association, TBA",
        "value": "381534777.35",
        "weight": "0.02911423",
        "shared": false
      },
      {
        "name": "G2 MA7589",
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        "weight": "0.02665257",
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      {
        "name": "G2 MA7051",
        "value": "330808305.53",
        "weight": "0.02524338",
        "shared": true
      },
      {
        "name": "G2 MB0686",
        "value": "288008133.05",
        "weight": "0.02197738",
        "shared": false
      },
      {
        "name": "G2 MA7649",
        "value": "256290540.77",
        "weight": "0.01955707",
        "shared": true
      },
      {
        "name": "GNII II 5.5% 03/01/2056 #TBA",
        "value": "228108632.90",
        "weight": "0.01740656",
        "shared": true
      },
      {
        "name": "G2 MB0747",
        "value": "221973651.70",
        "weight": "0.01693841",
        "shared": true
      },
      {
        "name": "G2 MA7192",
        "value": "220203914.33",
        "weight": "0.01680336",
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      },
      {
        "name": "G2 MA8800",
        "value": "212737911.16",
        "weight": "0.01623365",
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      {
        "name": "G2 MA7705",
        "value": "205796696.48",
        "weight": "0.01570397",
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      },
      {
        "name": "G2 MA8347",
        "value": "186183255.15",
        "weight": "0.01420731",
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      },
      {
        "name": "G2 MA6818",
        "value": "173846577.49",
        "weight": "0.01326592",
        "shared": true
      },
      {
        "name": "Government National Mortgage Association",
        "value": "167020523.31",
        "weight": "0.01274503",
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      },
      {
        "name": "G2 MA7650",
        "value": "163844262.64",
        "weight": "0.01250266",
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      },
      {
        "name": "G2 MA7312",
        "value": "162269318.76",
        "weight": "0.01238248",
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      },
      {
        "name": "G2 MA7311",
        "value": "141504404.39",
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      {
        "name": "G2 MA6864",
        "value": "137488638.09",
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        "name": "G2 MA7534",
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        "name": "G2 MB0624",
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        "name": "G2 MA4126",
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      {
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      {
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      {
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      {
        "name": "G2 MB0687",
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      {
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      {
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      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "79431407.81",
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      {
        "name": "GNMA II, Single-family, 30 Year",
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      },
      {
        "name": "UMBS, 30 Year",
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      {
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      {
        "name": "Government National Mortgage Association",
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      {
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      {
        "name": "G2 MA4778",
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      {
        "name": "GOVERNMENT NATIONAL MORTGAGE ASSOCIATION",
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      {
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    ]
  },
  "error": null,
  "sources": [
    {
      "label": "N-PORT (fund A)",
      "accession_no": "0001410368-26-039527",
      "as_of": "2026-02-28",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/1100663/000141036826039527/0001410368-26-039527-index.htm"
    },
    {
      "label": "N-PORT (fund B)",
      "accession_no": "0000106444-26-000139",
      "as_of": "2026-01-31",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/106444/000010644426000139/0000106444-26-000139-index.htm"
    }
  ]
}