<?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>
    <submissionType>NPORT-P</submissionType>
    <isConfidential>false</isConfidential>
    <filerInfo>

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


      <seriesClassInfo>
        <seriesId>S000003771</seriesId>
        <classId>C000010454</classId>
        <classId>C000010455</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>2020-03-31</repPdEnd>
      <repPdDate>2019-09-30</repPdDate>
      <isFinalFiling>N</isFinalFiling>
    </genInfo>
    <fundInfo>
      <totAssets>866375.72</totAssets>
      <totLiabs>2661.76</totLiabs>
      <netAssets>863713.96</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>
      <curMetrics>
        <curMetric>
          <curCd>USD</curCd>
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      <creditSprdRiskInvstGrade period10Yr="0.00000000" period1Yr="24.12359404" period30Yr="0.00000000" period3Mon="0.00000000" period5Yr="1.04451180"/>
      <creditSprdRiskNonInvstGrade period10Yr="0.00000000" period1Yr="0.00000000" period30Yr="0.00000000" period3Mon="0.00000000" period5Yr="0.00000000"/>
      <isNonCashCollateral>N</isNonCashCollateral>
      <returnInfo>
        <monthlyTotReturns>
          <monthlyTotReturn classId="C000010455" rtn1="-0.98865700" rtn2="4.23201100" rtn3="-2.82854800"/>
          <monthlyTotReturn classId="C000010454" rtn1="-0.98774600" rtn2="4.18043800" rtn3="-2.82725200"/>
          <monthlyTotReturn classId="C000010456" rtn1="-1.11456800" rtn2="3.86480100" rtn3="-3.10075000"/>
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        <monthlyReturnCats>
          <equityContracts>
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            <mon2 netRealizedGain="63836.15000000" netUnrealizedAppr="-25347.98000000"/>
            <mon3 netRealizedGain="-47227.82000000" netUnrealizedAppr="20336.73000000"/>
            <swapCategory>
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              <instrMon2 netRealizedGain="63836.15000000" netUnrealizedAppr="-25347.98000000"/>
              <instrMon3 netRealizedGain="-47227.82000000" netUnrealizedAppr="20336.73000000"/>
            </swapCategory>
          </equityContracts>
        </monthlyReturnCats>
        <othMon1 netRealizedGain="0.00000000" netUnrealizedAppr="-0.01000000"/>
        <othMon2 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
        <othMon3 netRealizedGain="0.00000000" netUnrealizedAppr="122.78000000"/>
      </returnInfo>
      <mon1Flow redemption="3274045.47000000" reinvestment="0.00000000" sales="3312954.82000000"/>
      <mon2Flow redemption="158932.45000000" reinvestment="0.00000000" sales="96084.47000000"/>
      <mon3Flow redemption="136397.57000000" reinvestment="0.00000000" sales="110999.70000000"/>


    </fundInfo>
    <invstOrSecs>
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        <lei>R0MUWSFPU8MPRO8K5P83</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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        <pctVal>0.279939900473</pctVal>
        <payoffProfile>N/A</payoffProfile>
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        <issuerConditional desc="Derivative" issuerCat="OTHER"/>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <derivativeInfo>
          <swapDeriv derivCat="SWP">
            <counterparties>
              <counterpartyName>BNP Paribas</counterpartyName>
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            <descRefInstrmnt>
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                <indexIdentifier>MID</indexIdentifier>
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            <swapFlag>Y</swapFlag>
            <floatingRecDesc curCd="USD" fixedOrFloating="Floating" floatingRtIndex="US0001M" floatingRtSpread="-0.05000000" pmntAmt="0.00000000">
              <rtResetTenors>
                <rtResetTenor rateTenor="Month" rateTenorUnit="1" resetDt="Month" resetDtUnit="1"/>
              </rtResetTenors>
            </floatingRecDesc>
            <otherPmntDesc fixedOrFloating="Other">S&amp;P MidCap 400 Index-Tenor Monthly</otherPmntDesc>
            <terminationDt>2019-10-29</terminationDt>
            <upfrontPmnt>0.00000000</upfrontPmnt>
            <pmntCurCd>USD</pmntCurCd>
            <upfrontRcpt>0.00000000</upfrontRcpt>
            <rcptCurCd>USD</rcptCurCd>
            <notionalAmt>-391729.93000000</notionalAmt>
            <curCd>USD</curCd>
            <unrealizedAppr>2417.88000000</unrealizedAppr>
          </swapDeriv>
        </derivativeInfo>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>Goldman Sachs International</name>
        <lei>W22LROWP2IHZNBB6K528</lei>
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        <identifiers>
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        </identifiers>
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        <units>NC</units>
        <curCd>USD</curCd>
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        <pctVal>0.037058565083</pctVal>
        <payoffProfile>N/A</payoffProfile>
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        <issuerConditional desc="Derivative" issuerCat="OTHER"/>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <derivativeInfo>
          <swapDeriv derivCat="SWP">
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              <counterpartyName>Goldman Sachs International</counterpartyName>
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              <indexBasketInfo>
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            <swapFlag>Y</swapFlag>
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            </floatingRecDesc>
            <otherPmntDesc fixedOrFloating="Other">S&amp;P MidCap 400 Index-Tenor Monthly</otherPmntDesc>
            <terminationDt>2019-10-28</terminationDt>
            <upfrontPmnt>0.00000000</upfrontPmnt>
            <pmntCurCd>USD</pmntCurCd>
            <upfrontRcpt>0.00000000</upfrontRcpt>
            <rcptCurCd>USD</rcptCurCd>
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            <curCd>USD</curCd>
            <unrealizedAppr>320.08000000</unrealizedAppr>
          </swapDeriv>
        </derivativeInfo>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>BOFA SECURITIES, INC.</name>
        <lei>549300HN4UKV1E2R3U73</lei>
        <title>Bank of America Merrill Lynch</title>
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        </identifiers>
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        <units>PA</units>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
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          <notClearedCentCparty isCleared="N">
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            </counterpartyInfos>
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          <isTriParty>Y</isTriParty>
          <repurchaseRt>2.28000000</repurchaseRt>
          <maturityDt>2019-10-01</maturityDt>
          <repurchaseCollaterals>
            <repurchaseCollateral>
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              <principalCd>USD</principalCd>
              <collateralVal>51155.37000000</collateralVal>
              <collateralCd>USD</collateralCd>
              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
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        <securityLending>
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          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
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      </invstOrSec>
      <invstOrSec>
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        <lei>G5GSEF7VJP5I7OUK5573</lei>
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        <identifiers>
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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">
            <counterparties>
              <counterpartyName>BARCLAYS BANK PLC</counterpartyName>
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            <descRefInstrmnt>
              <indexBasketInfo>
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                <indexIdentifier>MID</indexIdentifier>
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            <swapFlag>Y</swapFlag>
            <floatingRecDesc curCd="USD" fixedOrFloating="Floating" floatingRtIndex="US0001W" floatingRtSpread="0.20000000" pmntAmt="0.00000000">
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            <otherPmntDesc fixedOrFloating="Other">S&amp;P MidCap 400 Index-Tenor Monthly</otherPmntDesc>
            <terminationDt>2019-10-31</terminationDt>
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            <pmntCurCd>USD</pmntCurCd>
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      </invstOrSec>
      <invstOrSec>
        <name>J.P. MORGAN SECURITIES LLC</name>
        <lei>ZBUT11V806EZRVTWT807</lei>
        <title>JPMorgan Chase &amp; Co.</title>
        <cusip>N/A</cusip>
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          <other otherDesc="Internal ID" value="REPO-JP M"/>
        </identifiers>
        <balance>155962.39000000</balance>
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        <valUSD>155962.39000000</valUSD>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
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          <maturityDt>2019-10-01</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 Strategy Fund II</title>
        <cusip>N/A</cusip>
        <identifiers>
          <ticker value="GFSBX"/>
        </identifiers>
        <balance>12278.00800000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>304862.94000000</valUSD>
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        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
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          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>BARCLAYS CAPITAL INC.</name>
        <lei>AC28XWWI3WIBK2824319</lei>
        <title>Barclays Capital</title>
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          <other otherDesc="Internal ID" value="REPO-BARC"/>
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        <balance>45137.08000000</balance>
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        <curCd>USD</curCd>
        <valUSD>45137.08000000</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>
          <notClearedCentCparty isCleared="N">
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          <maturityDt>2019-10-01</maturityDt>
          <repurchaseCollaterals>
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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>30696.92800000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>305741.40000000</valUSD>
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        <assetCat>EC</assetCat>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
    </invstOrSecs>
    <signature>
      <ncom:dateSigned>2019-10-30</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>
