A 13F filing is a quarterly disclosure that institutional investment managers with over $100M in U.S.-listed securities must file with the SEC, listing their long equity positions within 45 days of each quarter end.
Form 13F is filed by "institutional investment managers" — hedge funds, mutual fund complexes, pensions, banks, and family offices — that exercise investment discretion over at least $100 million in Section 13(f) securities (mostly U.S.-exchange-listed stocks, plus some ETFs, options, and convertibles). It is due within 45 days after the end of each calendar quarter.
It is a powerful but partial lens. A 13F shows long positions in 13(f) securities only — it omits short positions, cash, most non-U.S. holdings, and small positions a manager may keep confidential under a granted delay. Because of the 45-day lag, the snapshot is always at least six weeks stale by the time it is public, so it is best read as a directional map of conviction, not a live book.
Berkshire Hathaway's 13F lists how many shares of each public company it held on the last day of the quarter, identified by CUSIP — but not its short hedges, private deals, or non-U.S. equities.
The 13F cluster is Arkolith's flagship dataset. We resolve the raw filings into clean, point-in-time fund holdings you can query by fund or by stock through one API/MCP call.
Arkolith turns this into live, sourced data your agent can query — SEC filings, insider activity, and market data behind one key, every datapoint traceable to its origin.