insider-dedup

What problem does it solve?

This Skill prevents inflated insider holdings and insider transaction counts caused by double-counting overlapping Schedule 13D/13G group filings and closely related Form 3/4/5/144 transactions.

Core Features & Use Cases

• Group and joint-filer deduplication: Treats related 13D/13G filings as one per-share position when the filings indicate shared group membership or joint reporting.
• Shared voting/dispositive power attribution: Counts shared-power shares once even when multiple filers report the same underlying position.
• Transaction-level dedup for Form 4: Identifies identical-tuple transactions reported by multiple related parties (e.g., executive, trust/LLC, spouse/dependent) and sums only the deduped economic events.
• Special-case guards: Excludes Form 144 from completed-sale tallies and avoids mixing unrelated filing types like 13F with 13D/13G ownership logic.
• Event-series correctness: Uses amendment-chain “latest holding” semantics per deduped group when building holdings and reconciles with expected deal/dilution signals.

Quick Start

Use insider-dedup to compute a deduplicated total insider holdings percentage from all 13D/13G (and amendments) for a given issuer within your target date window.