Herndon Mark — SEC Form 4 Insider Trading Activity

Summary

Updated Jul 16, 2026

Herndon Mark has filed 1 SEC Form 4 filing across 1 company in the last 90 days — buying. Lifetime open-market purchases: $5K.

Recent Transactions

DateTickerCompanyCodeSharesPriceValue
2026-05-21HKHCHorizon Kinetics Holding CorpP — Open-market purchase100$27.85$3K
2026-03-19HKHCHorizon Kinetics Holding CorpP — Open-market purchase80$33.03$3K

Companies — Last 90 Days

Frequently Asked Questions

Who is Herndon Mark?

Herndon Mark is a corporate insider — currently tracked as Chief Financial Officer of Horizon Kinetics Holding Corp (HKHC). InsiderAlpha tracks every SEC Form 4 filing in real time.

How many SEC Form 4 filings has Herndon Mark submitted recently?

1 primary Form 4 filings in the last 90 days, covering 1 company.

Has Herndon Mark been buying or selling stock?

Recorded transactions: 2 open-market purchases ($5K) and 0 open-market sales () across all tracked filings.

Where can I see all of Herndon Mark's SEC filings?

All Form 4 filings, transaction values, and 10b5-1 plan flags are listed on this page and updated in real time as new SEC EDGAR filings are processed.

Learn More

Open the live Herndon Mark profile on InsiderAlpha for real-time alerts, AI-scored trade ideas, and full transaction history.