Morgan, Lewis & Bockius LLP
1111 Pennsylvania Avenue, N.W.
Washington, D.C. 20004



September 7, 2007


VIA EDGAR

U.S. Securities and Exchange Commission
100 F Street, N.E.
Washington, D.C. 20549

Re:      RYDEX SERIES FUNDS (FILE NOS. 033-59692 AND 811-07584) AND RYDEX
         DYNAMIC FUNDS (FILE NOS. 333-84797 AND 811-09525)
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Ladies and Gentlemen:

On behalf of Rydex  Series  Funds and Rydex  Dynamic  Funds  (each a "Trust" and
together, the "Trusts"),  we are filing, pursuant to the Securities Exchange Act
of 1934 and the  Investment  Company Act of 1940,  a  definitive  Schedule  14A,
notice,  proxy statement and form of voting instruction for a Special Meeting of
Shareholders  ("Meeting") of the Trusts scheduled to be held on or about October
4, 2007.

The  Meeting  is  being  called  for the  purposes  of  approving  new  advisory
agreements between PADCO Advisors, Inc. and Rydex Series Funds and Rydex Dynamic
Funds and PADCO  Advisors II, Inc. and Rydex Variable Trust and Rydex ETF Trust,
as well as a new sub-advisory  agreement between PADCO Advisors II, Inc. and CLS
Investment Firm, LLC. It is anticipated that the current investment advisory and
sub-advisory agreements will terminate if and when a change of control occurs in
Rydex  Holdings,  Inc.,  the parent  company of PADCO  Advisors,  Inc. and PADCO
Advisors II, Inc.,  resulting from the transfer of ownership of Rydex  Holdings,
Inc. to  Security  Benefit  Corporation  and  Security  Benefit  Life  Insurance
Company.

The Trusts intend to mail definitive proxy materials to shareholders on or about
September  6, 2007.  Please  feel free to contact me at  202.739.5684  with your
questions or comments.

Sincerely,


/S/ LAURA E. FLORES
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Laura E. Flores