<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/nport" xmlns:com="http://www.sec.gov/edgar/common" xmlns:ncom="http://www.sec.gov/edgar/nportcommon" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.sec.gov/edgar/nport eis_NPORT_Filer.xsd">
  <headerData>
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    <isConfidential>false</isConfidential>
    <filerInfo>

      <filer>
        <issuerCredentials>
          <cik>0000899148</cik>
          <ccc>XXXXXXXX</ccc>
        </issuerCredentials>
      </filer>


      <seriesClassInfo>
        <seriesId>S000003771</seriesId>
        <classId>C000010455</classId>
        <classId>C000010454</classId>
        <classId>C000010456</classId>
      </seriesClassInfo>

    </filerInfo>
  </headerData>
  <formData>
    <genInfo>
      <regName>Rydex Series Funds</regName>
      <regFileNumber>811-07584</regFileNumber>
      <regCik>0000899148</regCik>
      <regLei>5493004D62WV1EDNTU07</regLei>
      <regStreet1>702 King Farm Blvd., Suite 200</regStreet1>
      <regCity>Rockville</regCity>
      <regStateConditional regCountry="US" regState="US-MD"/>
      <regZipOrPostalCode>20850</regZipOrPostalCode>
      <regPhone>301-296-5100</regPhone>
      <seriesName>Inverse Mid-Cap Strategy Fund</seriesName>
      <seriesId>S000003771</seriesId>
      <seriesLei>54930037B8QM4B0GQX38</seriesLei>
      <repPdEnd>2021-03-31</repPdEnd>
      <repPdDate>2020-09-30</repPdDate>
      <isFinalFiling>N</isFinalFiling>
    </genInfo>
    <fundInfo>
      <totAssets>1289675.70</totAssets>
      <totLiabs>10470.22</totLiabs>
      <netAssets>1279205.48</netAssets>
      <assetsAttrMiscSec>0.00000000</assetsAttrMiscSec>
      <assetsInvested>0.00000000</assetsInvested>
      <amtPayOneYrBanksBorr>0.00000000</amtPayOneYrBanksBorr>
      <amtPayOneYrCtrldComp>0.00000000</amtPayOneYrCtrldComp>
      <amtPayOneYrOthAffil>0.00000000</amtPayOneYrOthAffil>
      <amtPayOneYrOther>0.00000000</amtPayOneYrOther>
      <amtPayAftOneYrBanksBorr>0.00000000</amtPayAftOneYrBanksBorr>
      <amtPayAftOneYrCtrldComp>0.00000000</amtPayAftOneYrCtrldComp>
      <amtPayAftOneYrOthAffil>0.00000000</amtPayAftOneYrOthAffil>
      <amtPayAftOneYrOther>0.00000000</amtPayAftOneYrOther>
      <delayDeliv>0.00000000</delayDeliv>
      <standByCommit>0.00000000</standByCommit>
      <liquidPref>0.00000000</liquidPref>
      <cshNotRptdInCorD>0.00000000</cshNotRptdInCorD>
      <isNonCashCollateral>N</isNonCashCollateral>
      <returnInfo>
        <monthlyTotReturns>
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          <monthlyTotReturn classId="C000010454" rtn1="-4.73771200" rtn2="-3.50790500" rtn3="2.84843600"/>
          <monthlyTotReturn classId="C000010455" rtn1="-4.69146600" rtn2="-3.53138600" rtn3="2.86167900"/>
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        <monthlyReturnCats>
          <equityContracts>
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            <mon2 netRealizedGain="-48909.49000000" netUnrealizedAppr="-3678.65000000"/>
            <mon3 netRealizedGain="45075.88000000" netUnrealizedAppr="-9584.20000000"/>
            <swapCategory>
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              <instrMon3 netRealizedGain="45075.88000000" netUnrealizedAppr="-9584.20000000"/>
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        <othMon2 netRealizedGain="0.00000000" netUnrealizedAppr="965.98000000"/>
        <othMon3 netRealizedGain="0.00000000" netUnrealizedAppr="482.99000000"/>
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      <mon2Flow redemption="280721.32000000" reinvestment="0.00000000" sales="42667.34000000"/>
      <mon3Flow redemption="146671.11000000" reinvestment="0.00000000" sales="144277.13000000"/>


    </fundInfo>
    <invstOrSecs>
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        <curCd>USD</curCd>
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        <payoffProfile>N/A</payoffProfile>
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        <fairValLevel>2</fairValLevel>
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            <pmntCurCd>USD</pmntCurCd>
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        <securityLending>
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          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>BARCLAYS CAPITAL INC.</name>
        <lei>AC28XWWI3WIBK2824319</lei>
        <title>Barclays Capital, Inc.</title>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
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          <notClearedCentCparty isCleared="N">
            <counterpartyInfos>
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          <isTriParty>Y</isTriParty>
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          <maturityDt>2020-10-01</maturityDt>
          <repurchaseCollaterals>
            <repurchaseCollateral>
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              <principalCd>USD</principalCd>
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              <collateralCd>USD</collateralCd>
              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
        </repurchaseAgrmt>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
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        <lei>R0MUWSFPU8MPRO8K5P83</lei>
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        <identifiers>
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        <curCd>USD</curCd>
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        <payoffProfile>N/A</payoffProfile>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <derivativeInfo>
          <swapDeriv derivCat="SWP">
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              <counterpartyName>BNP Paribas</counterpartyName>
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            <descRefInstrmnt>
              <indexBasketInfo>
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            <swapFlag>Y</swapFlag>
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      <invstOrSec>
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        <fairValLevel>2</fairValLevel>
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          <maturityDt>2020-10-01</maturityDt>
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        <securityLending>
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          <isLoanByFund>N</isLoanByFund>
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      </invstOrSec>
      <invstOrSec>
        <name>Goldman Sachs International</name>
        <lei>W22LROWP2IHZNBB6K528</lei>
        <title>S&amp;P MidCap 400 Index</title>
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        <identifiers>
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        </identifiers>
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        <curCd>USD</curCd>
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        <fairValLevel>2</fairValLevel>
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      </invstOrSec>
      <invstOrSec>
        <name>Guggenheim Partners Investment Management LLC</name>
        <lei>N/A</lei>
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        <cusip>N/A</cusip>
        <identifiers>
          <ticker value="GFSBX"/>
        </identifiers>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
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      </invstOrSec>
      <invstOrSec>
        <name>BOFA SECURITIES, INC.</name>
        <lei>549300HN4UKV1E2R3U73</lei>
        <title>BofA Securities, Inc.</title>
        <cusip>N/A</cusip>
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          <other otherDesc="Internal ID" value="REPO-BANK"/>
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        <curCd>USD</curCd>
        <valUSD>224335.03000000</valUSD>
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        <payoffProfile>Long</payoffProfile>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
          <transCat>Repurchase</transCat>
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          <maturityDt>2020-10-01</maturityDt>
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              <invstCat>UST</invstCat>
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      </invstOrSec>
      <invstOrSec>
        <name>Guggenheim Partners Investment Management LLC</name>
        <lei>N/A</lei>
        <title>Guggenheim Ultra Short Duration Fund - Institutional Class</title>
        <cusip>40169J523</cusip>
        <identifiers>
          <isin value="US40169J5231"/>
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        <balance>16158.90900000</balance>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
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      </invstOrSec>
    </invstOrSecs>
    <signature>
      <ncom:dateSigned>2020-10-30</ncom:dateSigned>
      <ncom:nameOfApplicant>Rydex Series Funds</ncom:nameOfApplicant>
      <ncom:signature>John Sullivan</ncom:signature>
      <ncom:signerName>John Sullivan</ncom:signerName>
      <ncom:title>CFO</ncom:title>
    </signature>
  </formData>
</edgarSubmission>
