<?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">
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    <isConfidential>false</isConfidential>
    <filerInfo>

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


      <seriesClassInfo>
        <seriesId>S000003774</seriesId>
        <classId>C000010463</classId>
        <classId>C000010465</classId>
        <classId>C000010464</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>Commodities Strategy Fund</seriesName>
      <seriesId>S000003774</seriesId>
      <seriesLei>549300Y83L5ISW76HS10</seriesLei>
      <repPdEnd>2019-12-31</repPdEnd>
      <repPdDate>2019-12-31</repPdDate>
      <isFinalFiling>N</isFinalFiling>
    </genInfo>
    <fundInfo>
      <totAssets>5773349.56</totAssets>
      <totLiabs>13482.97</totLiabs>
      <netAssets>5759866.59</netAssets>
      <assetsAttrMiscSec>0</assetsAttrMiscSec>
      <assetsInvested>1018800.99</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>
      <isNonCashCollateral>N</isNonCashCollateral>
      <returnInfo>
        <monthlyTotReturns>
          <monthlyTotReturn classId="C000010463" rtn1="0.91092500" rtn2="0.24294900" rtn3="6.64210700"/>
          <monthlyTotReturn classId="C000010464" rtn1="0.91162300" rtn2="0.26067400" rtn3="6.62846700"/>
          <monthlyTotReturn classId="C000010465" rtn1="0.84394200" rtn2="0.18376500" rtn3="6.57129100"/>
        </monthlyTotReturns>
        <monthlyReturnCats>
          <commodityContracts>
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            <mon2 netRealizedGain="244101.00000000" netUnrealizedAppr="-232467.62000000"/>
            <mon3 netRealizedGain="14681.44000000" netUnrealizedAppr="348312.57000000"/>
            <futureCategory>
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              <instrMon2 netRealizedGain="244101.00000000" netUnrealizedAppr="-232467.62000000"/>
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            <mon2 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
            <mon3 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
            <futureCategory>
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              <instrMon2 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
              <instrMon3 netRealizedGain="0.00000000" netUnrealizedAppr="0.00000000"/>
            </futureCategory>
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        </monthlyReturnCats>
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        <othMon2 netRealizedGain="0.00000000" netUnrealizedAppr="-857.04000000"/>
        <othMon3 netRealizedGain="0.00000000" netUnrealizedAppr="-2661.48000000"/>
      </returnInfo>
      <mon1Flow redemption="752037.02000000" reinvestment="0.00000000" sales="1474199.79000000"/>
      <mon2Flow redemption="1811238.96000000" reinvestment="0.00000000" sales="1607671.23000000"/>
      <mon3Flow redemption="1931970.52000000" reinvestment="41263.67000000" sales="334275.25000000"/>


    </fundInfo>
    <invstOrSecs>
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        <name>J.P. MORGAN SECURITIES LLC</name>
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        <units>PA</units>
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        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>2</fairValLevel>
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          <maturityDt>2020-01-02</maturityDt>
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              <invstCat>UST</invstCat>
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          </repurchaseCollaterals>
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        <securityLending>
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          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
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      </invstOrSec>
      <invstOrSec>
        <name>BARCLAYS CAPITAL INC.</name>
        <lei>AC28XWWI3WIBK2824319</lei>
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        <fairValLevel>2</fairValLevel>
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          <notClearedCentCparty isCleared="N">
            <counterpartyInfos>
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          <maturityDt>2020-01-02</maturityDt>
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              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
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        <securityLending>
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          <isNonCashCollateral>N</isNonCashCollateral>
          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>Guggenheim Partners Investment Management LLC</name>
        <lei>N/A</lei>
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        <cusip>40169J523</cusip>
        <identifiers>
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        <balance>82715.84300000</balance>
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        <curCd>USD</curCd>
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        <invCountry>US</invCountry>
        <isRestrictedSec>N</isRestrictedSec>

        <fairValLevel>1</fairValLevel>
        <securityLending>
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          <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>200000.00000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>199713.06000000</valUSD>
        <pctVal>3.467320933209</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>
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          <isDefault>N</isDefault>
          <areIntrstPmntsInArrs>N</areIntrstPmntsInArrs>
          <isPaidKind>N</isPaidKind>
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        <securityLending>
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          <isLoanByFund>N</isLoanByFund>
        </securityLending>
      </invstOrSec>
      <invstOrSec>
        <name>Chicago Mercantile Exchange</name>
        <lei>N/A</lei>
        <title>Goldman Sachs Commodity Index Futures Contracts</title>
        <cusip>N/A</cusip>
        <identifiers>
          <ticker value="GIF0"/>
        </identifiers>
        <balance>53.00000000</balance>
        <units>NC</units>
        <curCd>USD</curCd>
        <valUSD>194903.11000000</valUSD>
        <pctVal>3.383812922653</pctVal>
        <payoffProfile>N/A</payoffProfile>
        <assetCat>DCO</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>
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            <payOffProf>Long</payOffProf>
            <descRefInstrmnt>
              <indexBasketInfo>
                <indexName>S&amp;P GSCI Index Spot CME</indexName>
                <indexIdentifier>SPGSCI</indexIdentifier>
              </indexBasketInfo>
            </descRefInstrmnt>
            <expDate>2020-01-16</expDate>
            <notionalAmt>5582096.89</notionalAmt>
            <curCd>USD</curCd>
            <unrealizedAppr>194903.11</unrealizedAppr>
          </futrDeriv>
        </derivativeInfo>
        <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>33050.81700000</balance>
        <units>NS</units>
        <curCd>USD</curCd>
        <valUSD>817677.21000000</valUSD>
        <pctVal>14.19611369852</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>
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      </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"/>
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        <balance>749783.28000000</balance>
        <units>PA</units>
        <curCd>USD</curCd>
        <valUSD>749783.28000000</valUSD>
        <pctVal>13.01737233466</pctVal>
        <payoffProfile>Long</payoffProfile>
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        <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>626101.70000000</principalAmt>
              <principalCd>USD</principalCd>
              <collateralVal>764780.16000000</collateralVal>
              <collateralCd>USD</collateralCd>
              <invstCat>UST</invstCat>
            </repurchaseCollateral>
          </repurchaseCollaterals>
        </repurchaseAgrmt>
        <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>
</edgarSubmission>
