Query fund holdings in two directions. Provide exactly one of `ticker` or `holding`. `?ticker=SPY` returns a fund's constituents and each position's weight (the fund's latest filing by default, or the composition in effect on/before `as_of`). `?holding=AAPL` returns the funds whose latest filing holds that security, sorted by weight.

The fund's ticker symbol (e.g., SPY). Returns that fund's holdings. Mutually exclusive with holding.

A held security's ticker symbol (e.g., AAPL). Returns the funds whose latest filing holds it. Mutually exclusive with ticker.

Only valid with ticker. Returns the fund composition in effect on or before this date (YYYY-MM-DD). Without it, the fund's latest filing is returned.

Only valid with ticker. Filter constituents by instrument type: equity or bond. Omit for all holdings.

The total number of rows to return (default: 50; 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.

The number of rows to skip, for pagination (default: 0).

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.