Amendments: when the filing you read gets replaced

13F-HR/A filings restate or patch earlier reports. How we keep the record straight.

A surprising share of 13F data changes after first publication. Managers file amendments (13F-HR/A) to fix errors, add omitted positions, or restate the entire table. An amendment can be a one-line patch or a complete replacement — the cover page says which, though not always clearly. Any pipeline that ignores amendments quietly serves wrong data; any pipeline that double-counts them serves wronger data.

How this site handles them

For each manager and quarter, the site keeps every filing event (original and amendments) in the filing record, but computes holdings from the latest accepted version: a restatement replaces the original table; an additive amendment merges with it. When an amendment changes a quarter that downstream statistics already used, the change engine and derived metrics recompute for the affected periods. The filings feed lists amendments explicitly, because a large manager restating a quarter is itself worth knowing.

Why totals sometimes shift under you

If you bookmarked a manager page last month and a number differs today, the likely cause is an amendment (the filing history at the bottom of the page will show it), a corporate action adjustment, or a metric-version update — in that order. Snapshot archive pages preserve each quarter's view as currently best known, not as first reported; where the two differ, the filing record holds both events with their dates.