{
  "page": "compare",
  "query": {
    "a": "FMSFX",
    "b": "FSIGX"
  },
  "retrieved_at": "2026-07-07T17:46:44+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": "Fidelity Advisor Mortgage Securities Fund",
    "ticker": "FMSFX",
    "slug": "FMSFX",
    "series_id": "S000005133",
    "html_url": "https://fundwatcher.app/funds/FMSFX/"
  },
  "fund_b": {
    "name": "Fidelity Series Investment Grade Bond Fund",
    "ticker": "FSIGX",
    "slug": "FSIGX",
    "series_id": "S000023604",
    "html_url": "https://fundwatcher.app/funds/FSIGX/"
  },
  "overlap": {
    "coverage_a_by_b": "0.1811546987617930453432250026",
    "coverage_b_by_a": "0.1811546987617930453432250026",
    "shared_count": 1064,
    "as_of": {
      "a": "2026-02-28",
      "b": "2026-02-28"
    },
    "a_top": [
      {
        "name": "GNII II 5.5% 03/01/2056 #TBA",
        "value": "84043377.80",
        "weight": "0.07009761",
        "shared": true
      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "71180704.40",
        "weight": "0.05936931",
        "shared": true
      },
      {
        "name": "G2SF 5.5 4/25",
        "value": "65439536.11",
        "weight": "0.05458080",
        "shared": true
      },
      {
        "name": "Government National Mortgage Association, TBA",
        "value": "48310513.69",
        "weight": "0.04029409",
        "shared": true
      },
      {
        "name": "Fidelity Cash Central Fund",
        "value": "43190155.63",
        "weight": "0.03602338",
        "shared": true
      },
      {
        "name": "FNCL 2 4/26",
        "value": "42488824.86",
        "weight": "0.03543842",
        "shared": true
      },
      {
        "name": "Fannie Mae or Freddie Mac",
        "value": "42232124.48",
        "weight": "0.03522432",
        "shared": true
      },
      {
        "name": "FNCL 6 3/24",
        "value": "28515633.16",
        "weight": "0.02378388",
        "shared": true
      },
      {
        "name": "FNCI 5 4/21",
        "value": "23716492.39",
        "weight": "0.01978109",
        "shared": true
      },
      {
        "name": "G2SF 6 4/25",
        "value": "20646541.58",
        "weight": "0.01722055",
        "shared": true
      },
      {
        "name": "G2 MA7986",
        "value": "16763505.43",
        "weight": "0.01398185",
        "shared": false
      },
      {
        "name": "US TREASURY N/B",
        "value": "16019906.25",
        "weight": "0.01336164",
        "shared": true
      },
      {
        "name": "FREDDIE MAC POOL FR SD0958",
        "value": "9347324.64",
        "weight": "0.00779627",
        "shared": false
      },
      {
        "name": "G2 MB0024",
        "value": "8994168.16",
        "weight": "0.00750172",
        "shared": false
      },
      {
        "name": "US TREASURY N/B",
        "value": "8438701.54",
        "weight": "0.00703842",
        "shared": false
      },
      {
        "name": "GNII II 6.5% 03/01/2056 #TBA",
        "value": "8313972.00",
        "weight": "0.00693439",
        "shared": true
      },
      {
        "name": "G2 MA7136",
        "value": "7849029.04",
        "weight": "0.00654660",
        "shared": false
      },
      {
        "name": "G2 MA7534",
        "value": "7805071.88",
        "weight": "0.00650993",
        "shared": false
      },
      {
        "name": "G2 MA7135",
        "value": "7651670.64",
        "weight": "0.00638199",
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      },
      {
        "name": "G2 MA7880",
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        "weight": "0.00614655",
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      },
      {
        "name": "G2 MA8043",
        "value": "7293301.83",
        "weight": "0.00608308",
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      },
      {
        "name": "FR SD8121",
        "value": "7183818.39",
        "weight": "0.00599177",
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      },
      {
        "name": "FNMA 15YR 2% 07/35#CA6242",
        "value": "7095550.57",
        "weight": "0.00591815",
        "shared": false
      },
      {
        "name": "G2 MA7988",
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        "weight": "0.00542819",
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      },
      {
        "name": "FR SD7535",
        "value": "5925093.07",
        "weight": "0.00494191",
        "shared": true
      },
      {
        "name": "Uniform Mortgage-Backed Securities",
        "value": "5513980.49",
        "weight": "0.00459902",
        "shared": false
      },
      {
        "name": "FORDF 2023-1 A1 144A 4.92% 05-15-28",
        "value": "5110184.70",
        "weight": "0.00426222",
        "shared": true
      },
      {
        "name": "ONEMAIN FINANCIAL ISSUANCE TRUST 2025-1 SER 2025-1A CL A REGD 144A P/P 4.82000000",
        "value": "5095313.00",
        "weight": "0.00424982",
        "shared": false
      },
      {
        "name": "FNCL 5.5 3/25",
        "value": "5080469.00",
        "weight": "0.00423744",
        "shared": true
      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "4984687.68",
        "weight": "0.00415755",
        "shared": true
      },
      {
        "name": "Freddie Mac Pool",
        "value": "4851274.13",
        "weight": "0.00404628",
        "shared": false
      },
      {
        "name": "FNMA 30YR 6% 11/01/2054#FA2958",
        "value": "4456713.59",
        "weight": "0.00371719",
        "shared": false
      },
      {
        "name": "Freddie Mac Multifamily Structured Pass Through Certificates",
        "value": "4397456.70",
        "weight": "0.00366776",
        "shared": true
      },
      {
        "name": "FNMA 30YR 2.5% 09/01/2050#FM4342",
        "value": "4033831.29",
        "weight": "0.00336448",
        "shared": true
      },
      {
        "name": "G2 MA6930",
        "value": "4017121.55",
        "weight": "0.00335054",
        "shared": false
      },
      {
        "name": "FNMA 30YR 6.5% 07/01/2054#CB8867",
        "value": "3697836.88",
        "weight": "0.00308423",
        "shared": true
      },
      {
        "name": "FNMA 30YR 3% 12/01/2049#FM2077",
        "value": "3653762.30",
        "weight": "0.00304747",
        "shared": false
      },
      {
        "name": "FNMA 30YR 6% 07/01/2055#FA3377",
        "value": "3653332.33",
        "weight": "0.00304712",
        "shared": false
      },
      {
        "name": "CGCMT 2016-P4 A4",
        "value": "3625137.56",
        "weight": "0.00302360",
        "shared": false
      },
      {
        "name": "Government National Mortgage Association",
        "value": "3608447.54",
        "weight": "0.00300968",
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      },
      {
        "name": "FR SD8106",
        "value": "3591486.86",
        "weight": "0.00299553",
        "shared": false
      },
      {
        "name": "FHLG 30YR 6.5% 09/01/2054#SD6617",
        "value": "3588569.64",
        "weight": "0.00299310",
        "shared": false
      },
      {
        "name": "BX TRUST",
        "value": "3541431.03",
        "weight": "0.00295378",
        "shared": true
      },
      {
        "name": "G2 MA7051",
        "value": "3336425.33",
        "weight": "0.00278279",
        "shared": false
      },
      {
        "name": "FNMA 30YR 2.5% 04/01/2052#FA2214",
        "value": "3246553.22",
        "weight": "0.00270784",
        "shared": false
      },
      {
        "name": "FR SD7530",
        "value": "3196343.96",
        "weight": "0.00266596",
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      },
      {
        "name": "FREDDIE MAC POOL FR RA5117",
        "value": "3070362.43",
        "weight": "0.00256088",
        "shared": false
      },
      {
        "name": "FHMS K555 SOFR30A+50 11/25/2030",
        "value": "3000449.70",
        "weight": "0.00250257",
        "shared": true
      },
      {
        "name": "FHLG 30YR 6% 02/01/2055#SL0360",
        "value": "2940042.11",
        "weight": "0.00245219",
        "shared": false
      },
      {
        "name": "FHLG 30YR 5.5% 03/01/2053#SD7559",
        "value": "2931763.89",
        "weight": "0.00244528",
        "shared": true
      }
    ],
    "b_top": [
      {
        "name": "Fidelity Cash Central Fund",
        "value": "1345626421.10",
        "weight": "0.03104402",
        "shared": true
      },
      {
        "name": "US TREASURY N/B",
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      },
      {
        "name": "US TREASURY N/B",
        "value": "749263265.63",
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      },
      {
        "name": "US TREASURY N/B",
        "value": "744711182.74",
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      {
        "name": "US TREASURY N/B",
        "value": "722487140.63",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "555646644.94",
        "weight": "0.01281894",
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      },
      {
        "name": "Government National Mortgage Association, TBA",
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        "weight": "0.01278954",
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      },
      {
        "name": "US TREASURY N/B",
        "value": "529760275.93",
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      },
      {
        "name": "US TREASURY N/B",
        "value": "527989800.00",
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      {
        "name": "US TREASURY N/B",
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      },
      {
        "name": "GNII II 5.5% 03/01/2056 #TBA",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "486318748.80",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "471392577.00",
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      },
      {
        "name": "FNCL 6 3/24",
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      },
      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
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      {
        "name": "US TREASURY N/B",
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      {
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      {
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      {
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      {
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "289918594.44",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "282750781.94",
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      },
      {
        "name": "Fannie Mae or Freddie Mac",
        "value": "264737554.36",
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      },
      {
        "name": "US TREASURY N/B",
        "value": "257396837.50",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "216066094.28",
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      },
      {
        "name": "Uniform Mortgage-Backed Security, TBA",
        "value": "210871283.96",
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        "shared": true
      },
      {
        "name": "US TREASURY N/B",
        "value": "204784452.12",
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      {
        "name": "US TREASURY N/B",
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      {
        "name": "US TREASURY N/B",
        "value": "197546562.50",
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      },
      {
        "name": "G2SF 6 4/25",
        "value": "189081537.54",
        "weight": "0.00436217",
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      },
      {
        "name": "FNCL 5.5 3/25",
        "value": "188383790.52",
        "weight": "0.00434607",
        "shared": true
      },
      {
        "name": "GNMA TBA",
        "value": "187532419.86",
        "weight": "0.00432643",
        "shared": false
      }
    ]
  },
  "error": null,
  "sources": [
    {
      "label": "N-PORT (fund A)",
      "accession_no": "0000035402-26-002564",
      "as_of": "2026-02-28",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/795422/000003540226002564/0000035402-26-002564-index.htm"
    },
    {
      "label": "N-PORT (fund B)",
      "accession_no": "0000035402-26-002637",
      "as_of": "2026-02-28",
      "edgar_url": "https://www.sec.gov/Archives/edgar/data/35315/000003540226002637/0000035402-26-002637-index.htm"
    }
  ]
}