Updated Jul 16, 2026 · Last SEC filing 2026-05-21
Horizon Kinetics Holding Corp (HKHC) has filed 2 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-05-21. 2 Form 8-K material event filings were reported by HKHC in the last 90 days. InsiderAlpha tracks every HKHC SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.
| SIC classification | Investment Advice (SIC 6282) |
|---|---|
| SEC CIK | 0000088000 |
| Form 4 filings (90d) | 2 |
|---|---|
| Form 8-K filings (90d) | 2 |
| Latest Form 4 filing | 2026-05-21 |
| Date | Insider | Role | Transaction | Shares | Price | Value | Filing |
|---|---|---|---|---|---|---|---|
| Herndon Mark | Chief Financial Officer | P — Open-market purchase | 100 | $27.85 | $3K | SEC | |
| Rosenthal Brent D | Director | P — Open-market purchase | 700 | $27.85 | $19K | SEC | |
| Nagelberg Allison | Director | P — Open-market purchase | 150 | $33.96 | $5K | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 10 | $34.60 | $346 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 18 | $34.60 | $623 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 25 | $34.60 | $865 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 18 | $34.06 | $613 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 46 | $34.06 | $2K | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 25 | $34.06 | $852 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 10 | $34.00 | $340 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 9 | $34.00 | $306 | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 8 | $34.00 | $272 | SEC | |
| Rosenthal Brent D | Director | P — Open-market purchase | 750 | $33.05 | $25K | SEC | |
| Herndon Mark | Chief Financial Officer | P — Open-market purchase | 80 | $33.03 | $3K | SEC | |
| STAHL MURRAY | CEO and CIO | P — Open-market purchase | 6 | $27.75 | $166 | SEC |
All transactions sourced from SEC EDGAR Form 4 filings for Horizon Kinetics Holding Corp (HKHC). Updated in real time as new filings are submitted to the SEC.
| Insider | Form 4 filings | Total transaction value |
|---|---|---|
| Rosenthal Brent D | 1 | $19K |
| Herndon Mark | 1 | $3K |
SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in HKHC insider filings:
| P | Open-market purchase by the insider |
|---|---|
| S | Open-market sale by the insider |
| A | Grant, award, or other acquisition from the issuer |
| M | Exercise or conversion of derivative security (e.g. options) |
| F | Payment of exercise price or tax liability via share withholding |
| G | Bona-fide gift of securities |
| D | Disposition to the issuer (e.g. share buyback participation) |
| J | Other acquisition or disposition |
| X | Exercise of in-the-money or at-the-money derivative security |
| C | Conversion of derivative security |
| V | Transaction voluntarily reported earlier than required |
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