Filings, funds, and the data behind them
Data readouts from 1.87M institutional positions across 1,824 filers, and guides to SEC filings, insider activity, and market data for AI agents. New articles daily.
Critical Third Parties: UK Cloud Rule Explained
A Critical Third Party is a provider whose service failure could threaten UK financial stability. The first UK designations are four cloud providers.
Market Data
34 posts
13F Holdings API: Query Funds, Stocks, Quarters
A 13F holdings API turns SEC institutional ownership filings into resolved fund, stock, quarter, and point-in-time queries with filing provenance.
What Is a Prime Broker? The Plumbing Behind Hedge Funds
Prime brokers are the custody, financing, and stock-loan layer under every hedge fund. None of it shows up in a 13F. Here is how the plumbing actually works.
Institutional Ownership: How to Find Who Owns a Stock
Institutional ownership is the share of a company held by funds rather than individuals. What it means, why the biggest holders are usually index funds, and how to read it.
Who Owns Walmart (WMT)? Institutional Ownership Map
More than 1,000 institutions disclose Walmart positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns JPMorgan Chase (JPM)? Ownership Map
More than 1,100 institutions disclose JPMorgan Chase positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns Costco (COST)? Institutional Ownership Map
673 institutions disclose Costco positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns Coinbase (COIN)? Institutional Ownership Map
More than 360 institutions disclose Coinbase positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
What Is a Security Master Database? A Builder's Guide
Every serious data shop builds a security master: the reference layer that maps identifiers, issuers, and corporate actions. Here is why it never stays clean.
Share Classes Explained: GOOG vs GOOGL and Dual-Class Stock
GOOG and GOOGL are both Alphabet but not the same security. How dual-class structures, separate CUSIPs, and lazy ticker joins corrupt holdings data.
Corporate Actions Data: Why Your Position Deltas Lie
Splits, spin-offs, mergers, and re-listings silently corrupt 13F position-change analytics. The detection signatures that separate real trades from paperwork.
Survivorship Bias in Fund Data: Why Dead Funds Matter
Funds that close simply stop filing, vanish from current-holdings datasets, and quietly flatter every backtest built on the survivors. The mechanism and the fix.
What Is Point-in-Time Data? Look-Ahead Bias Explained
Point-in-time data preserves what was known when, not just what happened. Why backtests fail without it, how 13F amendments rewrite history, and what bitemporal storage fixes.
Who Owns Disney (DIS)? Institutional Ownership Map
630 institutions disclose Walt Disney positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Entity Resolution in Financial Data: The Hard Problem
Two records, one company? Name variants, CIK vs LEI, and the manager-vs-fund split make entity resolution the quiet hard problem in financial data.
CUSIP vs ISIN vs FIGI vs Ticker: Which ID to Use
Every security carries at least four names. Here is how CUSIP, ISIN, FIGI, and tickers differ in scope, stability, and licensing, and when each breaks.
Who Owns Netflix (NFLX)? Institutional Ownership Map
More than 1,000 institutions disclose Netflix positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns AMD (AMD)? Institutional Ownership Map
630 institutions disclose AMD positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
SEC EDGAR API Guide: Fetching Filings Programmatically
How to pull SEC filings straight from EDGAR: the JSON endpoints, index files, and rate limits, plus the parsing traps that make raw EDGAR harder than it looks.
Who Owns Palantir (PLTR)? Institutional Ownership Map
More than 570 institutions disclose Palantir positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
13F Data Backtesting: Point-in-Time Discipline for Quants
Backtesting on 13F data fails quietly when holdings are joined to quarter-end dates instead of filing dates. The point-in-time rules that keep the research honest.
Who Owns Meta (META)? Institutional Ownership Map
770 institutions disclose Meta positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns Google (GOOGL)? Institutional Ownership Map
More than 800 institutions disclose Alphabet (Google) positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
How Accurate Is 13F Data? Seven Failure Modes to Know
A 13F is a legal disclosure, not a clean dataset. Seven specific ways raw filings mislead: option legs, amendments, identifier changes, misreported units, and more.
Who Owns Amazon (AMZN)? Institutional Ownership Map
More than 800 institutions disclose Amazon positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
13F Filing Deadlines in 2026: The Full Calendar
Every SEC 13F deadline for 2026, when filings actually land, and how to be ready the moment hedge fund holdings go public. Includes Form 4 and 13D timing.
Who Owns Tesla (TSLA)? Institutional Ownership Map
More than 670 institutions disclose Tesla in their 13F filings, about $151B in long value. The cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns Microsoft (MSFT)? Institutional Ownership Map
More than 800 institutions disclose Microsoft positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns Apple (AAPL)? Institutional Ownership Map
More than 760 institutions disclose Apple positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
Who Owns NVIDIA (NVDA)? Institutional Ownership Map
More than 800 institutions disclose NVIDIA positions in their 13F filings. Here is the real cap-table picture: the passive index core, the active money moving, and what 13F leaves out.
What Is a CUSIP? A Plain Guide for Holdings Data
A CUSIP is the 9-character ID that names a specific security in U.S. filings. Here is how it is built and why it matters when you work with holdings data.
13F vs 13D vs 13G vs Form 4: Who Owns What, Explained
Four SEC filings reveal who owns a stock, each with its own filer, threshold, and timing. Here is what 13F, 13D, 13G, and Form 4 actually tell you.
The Best Market Data APIs for AI Agents in 2026
If you are wiring market and financial data into an AI agent, the right API depends on what you need. A practical, honest comparison for 2026.
How to Read a 13F Filing (Fields, Timing, and Gotchas)
What a 13F filing is, who has to file one, the 45-day reporting lag, and the fields and gotchas that trip people up when reading institutional holdings.