A Central Index Key (CIK) is a unique identifier assigned by the SEC to each filer.

Why are some filings missing?

New filings appear as the SEC updates EDGAR, and older records can vary by availability.

How often is this page updated?

Updates follow new EDGAR submissions and periodic data refreshes.

SEC EDGAR filings, ownership reports, and insider transactions for John D. Duke.

Business address: C/O Harvard Bioscience, Inc., 84 October Hill Road, Holliston, MA, 01746
Top holdings (ownership): HBIO

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John D. Duke has filed 2 SEC EDGAR filings since 09 Jun 2025

Recent SEC filings for John D. Duke including 4, 3.

Form type	Document	Filing	Description	Filing date	Reporting date	File number(s)
4	Open 4 document	View SEC filing for 4	OWNERSHIP DOCUMENT	11 Aug 2025	08 Aug 2025	001-33957
3	Open 3 document	View SEC filing for 3	OWNERSHIP DOCUMENT	09 Jun 2025	02 Jun 2025	001-33957

John D. Duke files with the SEC under CIK 0002071593. This page aggregates EDGAR filings and related ownership activity.

What is a CIK?: A Central Index Key (CIK) is a unique identifier assigned by the SEC to each filer.
Why are some filings missing?: New filings appear as the SEC updates EDGAR, and older records can vary by availability.
How often is this page updated?: Updates follow new EDGAR submissions and periodic data refreshes.