# EDGAR Filing Document

**Accession Number:** 0001056823
**File Stem:** 0001056823-26-000009
**Filing Date:** 2026-4
**Character Count:** 14327
**Document Hash:** 6fcc5b65bef8447d7d9a1d18e5f1e114
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001056823-26-000009.hdr.sgml**: 20260428

**ACCESSION NUMBER**: 0001056823-26-000009

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 2

**FILED AS OF DATE**: 20260428

**DATE AS OF CHANGE**: 20260428

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MIAMI INTERNATIONAL HOLDINGS, INC.
- **CENTRAL INDEX KEY:** 0001438472
- **STANDARD INDUSTRIAL CLASSIFICATION:** SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
- **ORGANIZATION NAME:** 09 Crypto Assets
- **EIN:** 261482385
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-95202
- **FILM NUMBER:** 26906837

**BUSINESS ADDRESS:**
- **STREET 1:** 7 ROSZEL ROAD
- **STREET 2:** FIFTH FLOOR, SUITE 1-A
- **CITY:** PRINCETON
- **STATE:** NJ
- **ZIP:** 08540
- **BUSINESS PHONE:** 609-897-7300

**MAIL ADDRESS:**
- **STREET 1:** 7 ROSZEL ROAD
- **STREET 2:** FIFTH FLOOR, SUITE 1-A
- **CITY:** PRINCETON
- **STATE:** NJ
- **ZIP:** 08540

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MIAMI INTERNATIONAL HOLDINGS INC
- **DATE OF NAME CHANGE:** 20080624
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** HORIZON KINETICS ASSET MANAGEMENT LLC
- **CENTRAL INDEX KEY:** 0001056823

**ORGANIZATION NAME:**
- **EIN:** 133776334
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**BUSINESS ADDRESS:**
- **STREET 1:** 470 PARK AVENUE SOUTH
- **STREET 2:** 4TH FLOOR SOUTH
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10016
- **BUSINESS PHONE:** 646-495-7347

**MAIL ADDRESS:**
- **STREET 1:** 470 PARK AVENUE SOUTH
- **STREET 2:** 4TH FLOOR SOUTH
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10016

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** HORIZON ASSET MANAGEMENT LLC
- **DATE OF NAME CHANGE:** 20130813

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** HORIZON ASSET MANAGEMENT INC/NY
- **DATE OF NAME CHANGE:** 19990319

## Exhibit 99.1

------

---

| | | | | |
|:---|:---|:---|:---|:---|
| **Name of Reporting Person** | **Date of<br>Transaction** | **Buy/Sale** | **Aggregate<br>Amount of<br>Securities** | **Share<br>Price** |
| Horizon Kinetics Asset Management LLC | 2/26/2026 | BUY | 4176 | $42.11 |
| Horizon Kinetics Asset Management LLC | 2/27/2026 | BUY | 18688 | $42.85 |
| Horizon Kinetics Asset Management LLC | 3/2/2026 | BUY | 28706 | $42.34 |
| Horizon Kinetics Asset Management LLC | 3/3/2026 | BUY | 7608 | $42.67 |
| Horizon Kinetics Asset Management LLC | 3/4/2026 | BUY | 15408 | $43.38 |
| Horizon Kinetics Asset Management LLC | 3/5/2026 | BUY | 17918 | $42.86 |
| Horizon Kinetics Asset Management LLC | 3/6/2026 | BUY | 15150 | $42.06 |
| Horizon Kinetics Asset Management LLC | 3/9/2026 | BUY | 16745 | $40.56 |
| Horizon Kinetics Asset Management LLC | 3/10/2026 | BUY | 10741 | $40.82 |
| Horizon Kinetics Asset Management LLC | 3/11/2026 | BUY | 15296 | $39.27 |
| Horizon Kinetics Asset Management LLC | 3/12/2026 | BUY | 14311 | $38.42 |
| Horizon Kinetics Asset Management LLC | 3/13/2026 | BUY | 67294 | $38.46 |
| Horizon Kinetics Asset Management LLC | 3/16/2026 | BUY | 70337 | $39.32 |
| Horizon Kinetics Asset Management LLC | 3/17/2026 | BUY | 74852 | $39.77 |
| Horizon Kinetics Asset Management LLC | 3/17/2026 | SALE | 217 | $39.63 |
| Horizon Kinetics Asset Management LLC | 3/18/2026 | BUY | 98405 | $39.60 |
| Horizon Kinetics Asset Management LLC | 3/19/2026 | BUY | 34074 | $38.96 |
| Horizon Kinetics Asset Management LLC | 3/20/2026 | BUY | 100757 | $39.00 |
| Horizon Kinetics Asset Management LLC | 3/23/2026 | BUY | 86520 | $39.35 |
| Horizon Kinetics Asset Management LLC | 3/24/2026 | BUY | 89839 | $39.40 |

---

------

---

| | | | | |
|:---|:---|:---|:---|:---|
| Horizon Kinetics Asset Management LLC | 3/25/2026 | BUY | 92263 | $38.99 |
| Horizon Kinetics Asset Management LLC | 3/26/2026 | BUY | 115816 | $38.35 |
| Horizon Kinetics Asset Management LLC | 3/27/2026 | BUY | 18650 | $37.85 |
| Horizon Kinetics Asset Management LLC | 3/30/2026 | BUY | 39901 | $37.75 |
| Horizon Kinetics Asset Management LLC | 3/31/2026 | BUY | 10048 | $38.41 |
| Horizon Kinetics Asset Management LLC | 4/1/2026 | BUY | 11392 | $39.33 |
| Horizon Kinetics Asset Management LLC | 4/2/2026 | BUY | 55544 | $39.88 |
| Horizon Kinetics Asset Management LLC | 4/6/2026 | BUY | 24577 | $41.09 |
| Horizon Kinetics Asset Management LLC | 4/7/2026 | BUY | 18260 | $41.46 |
| Horizon Kinetics Asset Management LLC | 4/8/2026 | BUY | 11104 | $41.95 |
| Horizon Kinetics Asset Management LLC | 4/9/2026 | BUY | 4164 | $41.51 |
| Horizon Kinetics Asset Management LLC | 4/10/2026 | BUY | 4208 | $41.37 |
| Horizon Kinetics Asset Management LLC | 4/10/2026 | SALE | 184 | $41.34 |
| Horizon Kinetics Asset Management LLC | 4/13/2026 | BUY | 4685 | $42.36 |
| Horizon Kinetics Asset Management LLC | 4/14/2026 | BUY | 9312 | $43.33 |
| Horizon Kinetics Asset Management LLC | 4/15/2026 | BUY | 12516 | $43.84 |
| Horizon Kinetics Asset Management LLC | 4/16/2026 | BUY | 3970 | $44.29 |
| Horizon Kinetics Asset Management LLC | 4/17/2026 | BUY | 3906 | $45.28 |
| Horizon Kinetics Asset Management LLC | 4/20/2026 | BUY | 4248 | $44.97 |
| Horizon Kinetics Asset Management LLC | 4/21/2026 | BUY | 4282 | $45.17 |
| Horizon Kinetics Asset Management LLC | 4/21/2026 | SALE | 49 | $45.18 |

---

------

---

| | | | | |
|:---|:---|:---|:---|:---|
| Horizon Kinetics Asset Management LLC | 4/22/2026 | BUY | 6844 | $44.38 |
| Horizon Kinetics Asset Management LLC | 4/23/2026 | BUY | 4460 | $44.91 |
| Horizon Kinetics Asset Management LLC | 4/24/2026 | BUY | 6027 | $45.25 |
| Horizon Kinetics Asset Management LLC | 4/27/2026 | BUY | 36046 | $46.52 |

---

------

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 3)**

**MIAMI INTERNATIONAL HOLDINGS, INC.**

*(Name of Issuer)*

**Common Stock**

*(Title of Class of Securities)*

**—**

*(CUSIP Number)*

**Jay Kesslen**<br>470 Park Ave S<br>8th Floor South<br>New York NY 07030<br>2128671176

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**04/24/2026**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**HORIZON KINETICS ASSET MANAGEMENT LLC** | Name of reporting person<br>**HORIZON KINETICS ASSET MANAGEMENT LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**11162809.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**11162809.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11162809.00** | Aggregate amount beneficially owned by each reporting person<br>**11162809.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**12.2%** | Percent of class represented by amount in Row (11)<br>**12.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IA** | Type of Reporting Person (See Instructions)<br>**IA** | |

---

**Comment for Reporting Person:** Horizon Kinetics Asset Management LLC ("HKAM") is a Delaware limited liability company and a wholly owned subsidiary of Horizon Kinetics Holding Corporation ("HKHC"), a Delaware corporation, and manages funds and accounts ("Managed Accounts") that hold securities of the Issuer.

The following constitutes Amendment No. 3 to the schedule 13D filed by the undersigned. This Amendment No. 3 amends, supplements and to the extent inconsistent with, supersedes the initial Schedule 13D filed with the Securities and Exchange Commission on August 13, 2025, as amended by Amendment No. 1 filed November 24, 2025 and Amendment No. 2 filed April 14, 2026.

| **CUSIP No.** | **—** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Horizon Kinetics Holding Corp** | Name of reporting person<br>**Horizon Kinetics Holding Corp** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**11162809.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**11162809.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**11162809.00** | Aggregate amount beneficially owned by each reporting person<br>**11162809.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**12.2%** | Percent of class represented by amount in Row (11)<br>**12.2%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**HC** | Type of Reporting Person (See Instructions)<br>**HC** | |

---

**Comment for Reporting Person:** HKHC is the parent company to HKAM, a registered investment adviser. HKHC may be deemed to beneficially own the 11,162,809 shares beneficially owned by HKAM. HKHC has not entered into any separate transactions in the shares following the filing of Amendment No. 3 other than those listed under Schedule A, which were effectuated by HKAM.

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock

**(b) Name of Issuer:**
MIAMI INTERNATIONAL HOLDINGS, INC.

**(c) Address of Issuer's Principal Executive Offices:**
7 ROSZEL ROAD, FIFTH FLOOR, SUITE 1-A, PRINCETON, NJ, 08540

**Item 4. Purpose of Transaction**

Item 4 is hereby amended and restated in its entirety to read as follows:

HKAM acquired the securities reported herein on behalf of the Managed Accounts for investment purposes. In the ordinary course of its business, HKAM intends to regularly review its equity interest in the Issuer and may, from time to time, acquire additional shares or other securities of the Issuer. While HKAM has no present intention to dispose of all or any portion of the shares beneficially owned by Managed Accounts, it may sell shares from time to time for a number of reasons, not limited to client requests, regulatory or investment limitations or other reasons. Any such sales of securities of the Issuer may be in the open market, privately negotiated transactions or otherwise.

On April 24, 2026, Eric Sites, who serves as a Managing Director of HKAM, was elected to the Board of Directors of the Issuer.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Item 5 is hereby amended and restated in its entirety to read as follows:

As of the close of business on April 27, 2026, HKAM beneficially owned 11,162,809 shares of common stock.

The 11,162,809 shares beneficially owned represented 12.2% of the outstanding shares of common stock.

Neither the filing of this Schedule 13D nor any of its contents shall be deemed to constitute an admission that HKAM is the beneficial owner of the common stock referred to herein for purposes of Sections 13(d) and or 16 of the Securities Exchange Act of 1934, or for any other purpose, and such beneficial ownership is expressly disclaimed, except to the extent of its pecuniary interest therein.

On April 24, 2026, Eric Sites, who serves as a Managing Director of HKAM, was elected to the Board of Directors of the Issuer.

**(b)**
HKAM's Sole Power to vote is 11,162,809 shares.

**(c)**
Except as set forth in Schedule A attached hereto as Exhibit 99-a, HKAM has not effected any transaction in common stock in the past 60 days.

### SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** HORIZON KINETICS ASSET MANAGEMENT LLC

**Signature:** /s/ Jay Kesslen

**Name/Title:** Jay Kesslen, General Counsel

**Date:** 04/28/2026

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

**Reporting Person:** Horizon Kinetics Holding Corp

**Signature:** /s/ Jay Kesslen

**Name/Title:** Jay Kesslen, General Counsel

**Date:** 04/28/2026