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 WILLIAM C. KOSTUROS.

Business address: C/O Washington Mutual, Inc., 1301 Second Avenue, Seattle, WA, 98101

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WILLIAM C. KOSTUROS has filed 3 SEC EDGAR filings since 06 Mar 2003

Recent SEC filings for WILLIAM C. KOSTUROS including 3.

Form type	Document	Filing	Description	Filing date	Reporting date	File number(s)
3	Open 3 document	View SEC filing for 3	FORM 3 SUBMISSION	28 Apr 2023	13 Mar 2023	001-39154

WILLIAM C. KOSTUROS files with the SEC under CIK 0001221821. 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.