<?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>S000018293</seriesId>
        <classId>C000050430</classId>
        <classId>C000050428</classId>
        <classId>C000050429</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>Japan 2x Strategy Fund</seriesName>
      <seriesId>S000018293</seriesId>
      <seriesLei>549300TYQ6P1QBF6GR37</seriesLei>
      <repPdEnd>2020-03-31</repPdEnd>
      <repPdDate>2019-12-31</repPdDate>
      <isFinalFiling>N</isFinalFiling>
    </genInfo>
    <fundInfo>
      <totAssets>2086625.94</totAssets>
      <totLiabs>5531.8</totLiabs>
      <netAssets>2081094.14</netAssets>
      <assetsAttrMiscSec>0</assetsAttrMiscSec>
      <assetsInvested>0</assetsInvested>
      <amtPayOneYrBanksBorr>0</amtPayOneYrBanksBorr>
      <amtPayOneYrCtrldComp>0</amtPayOneYrCtrldComp>
      <amtPayOneYrOthAffil>0</amtPayOneYrOthAffil>
      <amtPayOneYrOther>0</amtPayOneYrOther>
      <amtPayAftOneYrBanksBorr>0</amtPayAftOneYrBanksBorr>
      <amtPayAftOneYrCtrldComp>0</amtPayAftOneYrCtrldComp>
      <amtPayAftOneYrOthAffil>0</amtPayAftOneYrOthAffil>
      <amtPayAftOneYrOther>0</amtPayAftOneYrOther>
      <delayDeliv>0</delayDeliv>
      <standByCommit>0</standByCommit>
      <liquidPref>0</liquidPref>
      <cshNotRptdInCorD>0</cshNotRptdInCorD>
      <curMetrics>
        <curMetric>
          <curCd>USD</curCd>
          <intrstRtRiskdv01 period10Yr="3.15813153" period1Yr="16.2548688" period30Yr="2.06578619" period3Mon="11.5075407" period5Yr="5.54500199"/>
          <intrstRtRiskdv100 period10Yr="315.81315261" period1Yr="1625.48687986" period30Yr="206.57861894" period3Mon="1150.75406964" period5Yr="554.50019945"/>
        </curMetric>
      </curMetrics>
      <creditSprdRiskInvstGrade period10Yr="0" period1Yr="53.75441533" period30Yr="0" period3Mon="4.84692535" period5Yr="14.88440346"/>
      <creditSprdRiskNonInvstGrade period10Yr="0" period1Yr="0" period30Yr="0" period3Mon="0" period5Yr="0"/>
      <isNonCashCollateral>N</isNonCashCollateral>
      <returnInfo>
        <monthlyTotReturns>
          <monthlyTotReturn classId="C000050430" rtn1="7.74164100" rtn2="2.26604300" rtn3="2.17425300"/>
          <monthlyTotReturn classId="C000050428" rtn1="7.74609700" rtn2="2.26195400" rtn3="2.17701800"/>
          <monthlyTotReturn classId="C000050429" rtn1="7.67953400" rtn2="2.18966500" rtn3="2.11940000"/>
        </monthlyTotReturns>
        <monthlyReturnCats>
          <equityContracts>
            <mon1 netRealizedGain="-18931.33000000" netUnrealizedAppr="185921.98000000"/>
            <mon2 netRealizedGain="4980.56000000" netUnrealizedAppr="120176.15000000"/>
            <mon3 netRealizedGain="381082.12000000" netUnrealizedAppr="-338122.64000000"/>
            <futureCategory>
              <instrMon1 netRealizedGain="-18931.33000000" netUnrealizedAppr="185921.98000000"/>
              <instrMon2 netRealizedGain="4980.56000000" netUnrealizedAppr="120176.15000000"/>
              <instrMon3 netRealizedGain="381082.12000000" netUnrealizedAppr="-338122.64000000"/>
            </futureCategory>
            <swapCategory>
              <instrMon1 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
              <instrMon2 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
              <instrMon3 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
            </swapCategory>
          </equityContracts>
          <foreignExchgContracts>
            <mon1 netRealizedGain="-12204.45000000" netUnrealizedAppr="8441.35000000"/>
            <mon2 netRealizedGain="-18796.50000000" netUnrealizedAppr="-51707.48000000"/>
            <mon3 netRealizedGain="-25880.07000000" netUnrealizedAppr="42236.58000000"/>
            <futureCategory>
              <instrMon1 netRealizedGain="-12204.45000000" netUnrealizedAppr="8441.35000000"/>
              <instrMon2 netRealizedGain="-18796.50000000" netUnrealizedAppr="-51707.48000000"/>
              <instrMon3 netRealizedGain="-25880.07000000" netUnrealizedAppr="42236.58000000"/>
            </futureCategory>
          </foreignExchgContracts>
        </monthlyReturnCats>
        <othMon1 netRealizedGain="1040.05000000" netUnrealizedAppr="-236.89000000"/>
        <othMon2 netRealizedGain="0.00000000" netUnrealizedAppr="-289.70000000"/>
        <othMon3 netRealizedGain="0.00000000" netUnrealizedAppr="-1782.85000000"/>
      </returnInfo>
      <mon1Flow redemption="1365678.61000000" reinvestment="0.00000000" sales="1269501.74000000"/>
      <mon2Flow redemption="1457300.44000000" reinvestment="0.00000000" sales="1328154.41000000"/>
      <mon3Flow redemption="1417610.71000000" reinvestment="16139.05000000" sales="872037.57000000"/>


    </fundInfo>
    <invstOrSecs>
      <invstOrSec>
        <name>J.P. MORGAN SECURITIES LLC</name>
        <lei>ZBUT11V806EZRVTWT807</lei>
        <title>J.P. Morgan Securities LLC</title>
        <cusip>N/A</cusip>
        <identifiers>
          <other otherDesc="Internal ID" value="REPO-JP M"/>
        </identifiers>
        <balance>451596.78000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>451596.78000000</valUSD>
        <pctVal>21.69996884427</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>RA</assetCat>
        <issuerCat>CORP</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
          <transCat>Repurchase</transCat>
          <notClearedCentCparty isCleared="N">
            <counterpartyInfos>
              <counterpartyInfo lei="ZBUT11V806EZRVTWT807" name="J.P. MORGAN SECURITIES LLC"/>
            </counterpartyInfos>
          </notClearedCentCparty>
          <isTriParty>Y</isTriParty>
          <repurchaseRt>1.53000000</repurchaseRt>
          <maturityDt>2020-01-02</maturityDt>
          <repurchaseCollaterals>
            <repurchaseCollateral>
              <principalAmt>417415.08000000</principalAmt>
              <principalCd>USD</principalCd>
              <collateralVal>460628.80000000</collateralVal>
              <collateralCd>USD</collateralCd>
              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
        </repurchaseAgrmt>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </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"/>
        </identifiers>
        <balance>39601.34100000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>394033.34000000</valUSD>
        <pctVal>18.93395077264</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>Chicago Mercantile Exchange</name>
        <lei>N/A</lei>
        <title>Japanese Yen Futures Contracts</title>
        <cusip>N/A</cusip>
        <identifiers>
          <ticker value="JYH0"/>
        </identifiers>
        <balance>37.00000000</balance>
        <units>NC</units>
        <curCd>USD</curCd>
        <valUSD>-11366.75000000</valUSD>
        <pctVal>-0.54619105313</pctVal>
        <payoffProfile>N/A</payoffProfile>
        <assetCat>DFE</assetCat>
        <issuerConditional desc="Derivative" issuerCat="OTHER"/>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <derivativeInfo>
          <futrDeriv derivCat="FUT">
            <counterparties>
              <counterpartyName>Goldman Sachs &amp; Co. LLC</counterpartyName>
              <counterpartyLei>FOR8UP27PHTHYVLBNG30</counterpartyLei>
            </counterparties>
            <payOffProf>Long</payOffProf>
            <descRefInstrmnt>
              <otherRefInst>
                <issuerName>N/A</issuerName>
                <issueTitle>Japanese Yen</issueTitle>
                <identifiers>
                  <cusip value="N/A"/>
                  <other otherDesc="Currency" value="Japanese Yen"/>
                </identifiers>
              </otherRefInst>
            </descRefInstrmnt>
            <expDate>2020-03-16</expDate>
            <notionalAmt>4284404.25</notionalAmt>
            <curCd>USD</curCd>
            <unrealizedAppr>-11366.75</unrealizedAppr>
          </futrDeriv>
        </derivativeInfo>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>FEDERAL FARM CREDIT BANK</name>
        <lei>N/A</lei>
        <title>Federal Farm Credit Bank</title>
        <cusip>3133EKGP5</cusip>
        <identifiers>
          <isin value="US3133EKGP58"/>
        </identifiers>
        <balance>100000.00000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>99977.14000000</valUSD>
        <pctVal>4.804066191835</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>DBT</assetCat>
        <issuerCat>USGSE</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <debtSec>
          <maturityDt>2022-04-11</maturityDt>
          <couponKind>Floating</couponKind>
          <annualizedRt>1.81600000</annualizedRt>
          <isDefault>N</isDefault>
          <areIntrstPmntsInArrs>N</areIntrstPmntsInArrs>
          <isPaidKind>N</isPaidKind>
        </debtSec>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>BOFA SECURITIES, INC.</name>
        <lei>549300HN4UKV1E2R3U73</lei>
        <title>BofA Securities, Inc.</title>
        <cusip>N/A</cusip>
        <identifiers>
          <other otherDesc="Internal ID" value="REPO-BANK"/>
        </identifiers>
        <balance>145615.59000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>145615.59000000</valUSD>
        <pctVal>6.997068859172</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>RA</assetCat>
        <issuerCat>CORP</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
          <transCat>Repurchase</transCat>
          <notClearedCentCparty isCleared="N">
            <counterpartyInfos>
              <counterpartyInfo lei="549300HN4UKV1E2R3U73" name="BOFA SECURITIES, INC."/>
            </counterpartyInfos>
          </notClearedCentCparty>
          <isTriParty>Y</isTriParty>
          <repurchaseRt>1.50000000</repurchaseRt>
          <maturityDt>2020-01-02</maturityDt>
          <repurchaseCollaterals>
            <repurchaseCollateral>
              <principalAmt>121595.36000000</principalAmt>
              <principalCd>USD</principalCd>
              <collateralVal>148528.14000000</collateralVal>
              <collateralCd>USD</collateralCd>
              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
        </repurchaseAgrmt>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>BARCLAYS CAPITAL INC.</name>
        <lei>AC28XWWI3WIBK2824319</lei>
        <title>Barclays Capital, Inc.</title>
        <cusip>N/A</cusip>
        <identifiers>
          <other otherDesc="Internal ID" value="REPO-BARC"/>
        </identifiers>
        <balance>145615.59000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>145615.59000000</valUSD>
        <pctVal>6.997068859172</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>RA</assetCat>
        <issuerCat>CORP</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <repurchaseAgrmt>
          <transCat>Repurchase</transCat>
          <notClearedCentCparty isCleared="N">
            <counterpartyInfos>
              <counterpartyInfo lei="AC28XWWI3WIBK2824319" name="BARCLAYS CAPITAL INC."/>
            </counterpartyInfos>
          </notClearedCentCparty>
          <isTriParty>Y</isTriParty>
          <repurchaseRt>1.40000000</repurchaseRt>
          <maturityDt>2020-01-02</maturityDt>
          <repurchaseCollaterals>
            <repurchaseCollateral>
              <principalAmt>147274.04000000</principalAmt>
              <principalCd>USD</principalCd>
              <collateralVal>148527.96000000</collateralVal>
              <collateralCd>USD</collateralCd>
              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
        </repurchaseAgrmt>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>FEDERAL FARM CREDIT BANK</name>
        <lei>N/A</lei>
        <title>Federal Farm Credit Bank</title>
        <cusip>3133EKCY0</cusip>
        <identifiers>
          <isin value="US3133EKCY02"/>
        </identifiers>
        <balance>100000.00000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>100196.56000000</valUSD>
        <pctVal>4.814609684115</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>DBT</assetCat>
        <issuerCat>USGSE</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <debtSec>
          <maturityDt>2022-03-14</maturityDt>
          <couponKind>Floating</couponKind>
          <annualizedRt>1.95000000</annualizedRt>
          <isDefault>N</isDefault>
          <areIntrstPmntsInArrs>N</areIntrstPmntsInArrs>
          <isPaidKind>N</isPaidKind>
        </debtSec>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>Chicago Mercantile Exchange</name>
        <lei>N/A</lei>
        <title>Nikkei 225 (CME) Index Futures Contracts</title>
        <cusip>N/A</cusip>
        <identifiers>
          <ticker value="NXH0"/>
        </identifiers>
        <balance>37.00000000</balance>
        <units>NC</units>
        <curCd>USD</curCd>
        <valUSD>19149.40000000</valUSD>
        <pctVal>0.920160199960</pctVal>
        <payoffProfile>N/A</payoffProfile>
        <assetCat>DE</assetCat>
        <issuerConditional desc="Derivative" issuerCat="OTHER"/>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <derivativeInfo>
          <futrDeriv derivCat="FUT">
            <counterparties>
              <counterpartyName>Goldman Sachs &amp; Co. LLC</counterpartyName>
              <counterpartyLei>FOR8UP27PHTHYVLBNG30</counterpartyLei>
            </counterparties>
            <payOffProf>Long</payOffProf>
            <descRefInstrmnt>
              <indexBasketInfo>
                <indexName>Nikkei 225</indexName>
                <indexIdentifier>JP9010C00002</indexIdentifier>
              </indexBasketInfo>
            </descRefInstrmnt>
            <expDate>2020-03-12</expDate>
            <notionalAmt>4323725.6</notionalAmt>
            <curCd>USD</curCd>
            <unrealizedAppr>19149.4</unrealizedAppr>
          </futrDeriv>
        </derivativeInfo>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>TREASURY BILL</name>
        <lei>254900HROIFWPRGM1V77</lei>
        <title>U.S. Treasury Bills</title>
        <cusip>912796WR6</cusip>
        <identifiers>
          <isin value="US912796WR64"/>
        </identifiers>
        <balance>183000.00000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>182737.45000000</valUSD>
        <pctVal>8.780835354233</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>DBT</assetCat>
        <issuerCat>UST</issuerCat>
        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
        <debtSec>
          <maturityDt>2020-02-04</maturityDt>
          <couponKind>None</couponKind>
          <annualizedRt>0.00000000</annualizedRt>
          <isDefault>N</isDefault>
          <areIntrstPmntsInArrs>N</areIntrstPmntsInArrs>
          <isPaidKind>N</isPaidKind>
        </debtSec>
        <securityLending>
          <isCashCollateral>N</isCashCollateral>
          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </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>22246.55700000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>550379.82000000</valUSD>
        <pctVal>26.44665656499</pctVal>
        <payoffProfile>Long</payoffProfile>
        <assetCat>EC</assetCat>
        <issuerCat>RF</issuerCat>
        <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>2020-01-30</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>
  <documents>XXXX</documents>
</edgarSubmission>
