{
  "page": "compare",
  "query": {
    "a": "MBB",
    "b": "HCASX"
  },
  "retrieved_at": "2026-07-07T15:24:19+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": "The U.S. Mortgage/Asset Backed Fixed Income Securities Portfolio",
    "ticker": "HCASX",
    "slug": "HCASX",
    "series_id": "S000029854",
    "html_url": "https://fundwatcher.app/funds/HCASX/"
  },
  "overlap": {
    "coverage_a_by_b": "0.1074240102792591416236050841",
    "coverage_b_by_a": "0.1074240102792591416236050841",
    "shared_count": 567,
    "as_of": {
      "a": "2026-02-28",
      "b": "2025-12-31"
    },
    "a_top": [
      {
        "name": "BlackRock Cash Funds: Treasury, SL Agency Shares",
        "value": "2349848882.32",
        "weight": "0.05655290",
        "shared": false
      },
      {
        "name": "FR SD8146",
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        "weight": "0.01029064",
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      },
      {
        "name": "GNII II 5.5% 03/01/2056 #TBA",
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      },
      {
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      },
      {
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      },
      {
        "name": "FN MA4492",
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      },
      {
        "name": "G2SF 5 3/25",
        "value": "209896727.56",
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      },
      {
        "name": "FR SD8140",
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      },
      {
        "name": "FNCL 5.5 3/25",
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        "name": "G2 MA7472",
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      },
      {
        "name": "Government National Mortgage Association, TBA",
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      },
      {
        "name": "FN MA4465",
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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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      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
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      },
      {
        "name": "FR SD8199",
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      },
      {
        "name": "FN MA4281",
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      },
      {
        "name": "Fannie Mae Pool",
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      },
      {
        "name": "G2 MA9171",
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        "name": "FN MA4437",
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      {
        "name": "FN MA4305",
        "value": "120559723.67",
        "weight": "0.00290146",
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      },
      {
        "name": "Fannie Mae Pool",
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      },
      {
        "name": "G2 MA7936",
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      {
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      {
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      {
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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",
        "weight": "0.00233319",
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      },
      {
        "name": "FANNIE MAE POOL FN 05/52 FIXED VAR",
        "value": "93078582.60",
        "weight": "0.00224009",
        "shared": false
      },
      {
        "name": "G2 MA9781",
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      {
        "name": "G2 MA7987",
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        "name": "G2 MA7589",
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      {
        "name": "FR SD8134",
        "value": "90692946.45",
        "weight": "0.00218267",
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      {
        "name": "FR SD8362",
        "value": "90321930.34",
        "weight": "0.00217374",
        "shared": true
      },
      {
        "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",
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      },
      {
        "name": "G2 MA9852",
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        "weight": "0.00204082",
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      },
      {
        "name": "Uniform Mortgage-Backed Securities",
        "value": "82184209.52",
        "weight": "0.00197790",
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      },
      {
        "name": "G2 MB0091",
        "value": "80607537.41",
        "weight": "0.00193995",
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      },
      {
        "name": "Freddie Mac Pool",
        "value": "79799967.76",
        "weight": "0.00192051",
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      },
      {
        "name": "FR SD8234",
        "value": "77789632.23",
        "weight": "0.00187213",
        "shared": false
      }
    ],
    "b_top": [
      {
        "name": "Vanguard Scottsdale Funds INTERMEDIATE-TERM TREASURY",
        "value": "32416616.44",
        "weight": "0.11676801",
        "shared": false
      },
      {
        "name": "SS INST TREAS PLUS MM FUN",
        "value": "22564754.30",
        "weight": "0.08128058",
        "shared": false
      },
      {
        "name": "ISHARES US TREASURY BOND ETF",
        "value": "6004114.13",
        "weight": "0.02162744",
        "shared": false
      },
      {
        "name": "FNCL 2 1/26",
        "value": "2000592.77",
        "weight": "0.00720634",
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      },
      {
        "name": "FNCL 6 1/26",
        "value": "1488402.35",
        "weight": "0.00536138",
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      {
        "name": "FNCL 2.5 1/26",
        "value": "1457827.15",
        "weight": "0.00525124",
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      },
      {
        "name": "FNCL 5.5 1/26",
        "value": "1166216.79",
        "weight": "0.00420083",
        "shared": false
      },
      {
        "name": "FNCL 3 1/26",
        "value": "1061578.13",
        "weight": "0.00382391",
        "shared": false
      },
      {
        "name": "G2 MA7704",
        "value": "858755.21",
        "weight": "0.00309333",
        "shared": true
      },
      {
        "name": "FNCL 4 1/26",
        "value": "758625.00",
        "weight": "0.00273265",
        "shared": false
      },
      {
        "name": "G2SF 5 1/26",
        "value": "723045.90",
        "weight": "0.00260449",
        "shared": false
      },
      {
        "name": "FNCL 4.5 1/26",
        "value": "683101.57",
        "weight": "0.00246060",
        "shared": false
      },
      {
        "name": "G2SF 3 1/26",
        "value": "629781.25",
        "weight": "0.00226854",
        "shared": false
      },
      {
        "name": "G2 MB0025",
        "value": "613526.90",
        "weight": "0.00220999",
        "shared": true
      },
      {
        "name": "G2 MB0742",
        "value": "607306.44",
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      },
      {
        "name": "G2SF 6 1/25",
        "value": "585781.25",
        "weight": "0.00211004",
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      },
      {
        "name": "Government National Mortgage Association, TBA",
        "value": "582609.38",
        "weight": "0.00209862",
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      {
        "name": "G2 MB0090",
        "value": "564888.29",
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      },
      {
        "name": "G2 MA8428",
        "value": "563934.25",
        "weight": "0.00203135",
        "shared": false
      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "556896.48",
        "weight": "0.00200600",
        "shared": false
      },
      {
        "name": "FNCL 5 1/26",
        "value": "548646.48",
        "weight": "0.00197628",
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      },
      {
        "name": "G2 MA7589",
        "value": "548179.95",
        "weight": "0.00197460",
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      {
        "name": "G2 MA7417",
        "value": "544823.12",
        "weight": "0.00196251",
        "shared": true
      },
      {
        "name": "G2SF 4 1/26",
        "value": "543105.47",
        "weight": "0.00195632",
        "shared": false
      },
      {
        "name": "Freddie Mac Pool",
        "value": "520588.65",
        "weight": "0.00187521",
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      },
      {
        "name": "FNCL 6.5 1/26",
        "value": "519628.91",
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      },
      {
        "name": "FNCI 2 1/26",
        "value": "509287.11",
        "weight": "0.00183450",
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      },
      {
        "name": "Federal National Mortgage Association, Inc.",
        "value": "506323.42",
        "weight": "0.00182383",
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      },
      {
        "name": "FEDERAL HOME LOAN MORTGAGE CORPORATION",
        "value": "490040.83",
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      },
      {
        "name": "FNMA POOL CB7651 FN 12/53 FIXED 6.5",
        "value": "486517.66",
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      },
      {
        "name": "FNCL 3.5 1/26",
        "value": "485501.95",
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      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "482299.81",
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      },
      {
        "name": "G2SF 3.5 1/26",
        "value": "477750.00",
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      {
        "name": "G2 MA8877",
        "value": "473903.36",
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      {
        "name": "G2 MB0092",
        "value": "459203.52",
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      {
        "name": "FR SD8214",
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      },
      {
        "name": "FR SD6764",
        "value": "434953.16",
        "weight": "0.00156675",
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      },
      {
        "name": "FNMA UMBS, 30 Year",
        "value": "434007.16",
        "weight": "0.00156334",
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      },
      {
        "name": "G2 MB0145",
        "value": "425112.96",
        "weight": "0.00153130",
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      },
      {
        "name": "UMBS",
        "value": "423732.87",
        "weight": "0.00152633",
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      },
      {
        "name": "G2 MB0146",
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      },
      {
        "name": "FN CB9309",
        "value": "421997.76",
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      {
        "name": "FN MA5585",
        "value": "420699.27",
        "weight": "0.00151540",
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      },
      {
        "name": "Freddie Mac Pool",
        "value": "420280.29",
        "weight": "0.00151389",
        "shared": false
      },
      {
        "name": "UMBS",
        "value": "420228.57",
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      {
        "name": "FR SD8505",
        "value": "419146.95",
        "weight": "0.00150981",
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      },
      {
        "name": "FR SD8491",
        "value": "417776.13",
        "weight": "0.00150487",
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      },
      {
        "name": "Federal National Mortgage Association, Inc.",
        "value": "411842.14",
        "weight": "0.00148350",
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      },
      {
        "name": "FN MA5107",
        "value": "409828.87",
        "weight": "0.00147625",
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      },
      {
        "name": "Federal National Mortgage Association, Inc.",
        "value": "408992.14",
        "weight": "0.00147323",
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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": "0001004726-26-001165",
      "as_of": "2025-12-31",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/934563/000100472626001165/0001004726-26-001165-index.htm"
    }
  ]
}