Query 13F institutional holdings by filer CIK or by held ticker. Provide exactly one of `filer_cik` or `ticker`. When no `report_period` filter is supplied, `?filer_cik=...` returns the filer's most recent 13F and `?ticker=...` returns one position per institutional filer whose most recent 13F currently includes the ticker (filers who have since dropped the position are excluded).

The 10-digit zero-padded SEC CIK of the institutional filer. Mutually exclusive with ticker.

The held security's ticker symbol. Mutually exclusive with filer_cik. Without a report_period filter, returns one position per institutional filer whose most recent 13F currently includes this ticker.

The total number of rows to return (default: 10; no maximum). This is the total across all pages, not a page size: each page holds up to 10 records, linked by next_page_url.

Opaque pagination cursor from a previous response's next_page_url. When provided, all other query parameters are ignored: the cursor carries the original request's filters. Treat it as opaque; do not construct or modify it.