EX.99.906CERT

         CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT

Peter B. Doyle, President, and Leonid Polyakov, Treasurer, of each of Kinetics
Mutual Funds, Inc. and Kinetics Portfolio Trust (each, the "Registrant"), each
certify to the best of his knowledge that:

1.       The Registrant's periodic report on Form N-CSR for the period ended
         December 31, 2004 (the "Form N-CSR") fully complies with the
         requirements of section 15(d) of the Securities Exchange Act of 1934,
         as amended; and

2.       The information contained in the Form N-CSR fairly presents, in all
         material respects, the financial condition and results of operations of
         the Registrant.



/s/ Peter B. Doyle                        /s/ Leonid Polyakov
- --------------------------------------    --------------------------------------
Peter B. Doyle                            Leonid Polyakov
President, Kinetics Mutual Funds, Inc.    Treasurer, Kinetics Mutual Funds, Inc.
& Kinetics Portfolios Trust               & Kinetics Portfolios Trust

Dated: March 11, 2005
       -------------------------------


This certification is being furnished to the Securities and Exchange Commission
pursuant to Rule 30a-2(b) under the Investment Company Act of 1940, as amended,
and 18 U.S.C. Section 1350 and is not being filed as part of the Form N-CSR with
the Securities and Exchange Commission.