POWER OF ATTORNEY

      The undersigned hereby appoints Jay Kesslen as attorney-in-fact
and agent, with the power, to (a) execute for and on behalf of
the undersigned, in the undersigneds capacity as an officer/director of
Horizon Kinetics Holding Corporation (Company), Forms 3, 4 and 5 in
accordance with Section 16(a) of the Securities Exchange Act of 1934
and the rules thereunder; (b) do and perform any and all acts for and on
behalf of the undersigned which may be necessary or desirable to complete
and execute any such Form 3, 4 or 5, complete and execute any amendment or
amendments thereto, and timely file with the U.S. Securities and Exchange
Commission and any stock exchange or similar authority; and (c) take any
other action of any type whatsoever in connection with the foregoing which,
in the opinion of such attorney-in-fact, may be of benefit to, in the
best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf
of the undersigned pursuant to this Power of Attorney shall be in such
form and shall contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-facts discretion.

      The undersigned hereby grants to such attorney-in-fact full power
and authority to do and perform any and every act and thing whatsoever
requisite, necessary or proper to be done in the exercise of any of the
rights and powers granted herein, as fully to all intents and purposes as
the undersigned might or could do if personally present, with full power
of substitution or revocation, hereby ratifying and confirming all that
such attorney-in-fact, or such attorney-in-facts substitute or substitutes,
shall lawfully do or cause to be done by virtue of this Power of Attorney
and the right and powers herein granted. The undersigned acknowledges that
the foregoing attorney-in-fact, in serving in such capacity at the request
of the undersigned, is not assuming, nor is the Company assuming, any
of the undersigneds responsibilities to comply with Section 16
of the Securities Exchange Act of 1934.

      This Power of Attorney shall remain in full force and
effect until the undersigned is no longer required to file Forms
3, 4 and 5 with respect to the undersigneds holdings of and
transaction in securities issued by the Company, unless earlier
revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

      IN WITNESS WHEREOF, the undersigned has caused this Power
of Attorney to be executed as of this 7th day of August 2024.
Signature					/s/Brent Rosenthal
GIVEN UNDER MY HAND AND SEAL OF OFFICE, this 6th day of August 2024.
Signature					/s/Russell Grimaldi
Notary Public in and for The State of New York
My commission expires	May 15, 2025