13F, Form 4 & Congressional Trading FAQ

What is a 13F filing?

A Form 13F is a quarterly disclosure that large institutional investment managers must file with the US Securities and Exchange Commission (SEC). It lists every US-listed equity security the manager held as of the last day of the quarter.

13F filings are public record and available on SEC EDGAR. They are the primary window the public has into the portfolios of major hedge funds, asset managers, and endowments. 13FAI automates the collection and analysis of these filings so you don't have to read raw SEC documents.

Who is required to file?

Any institutional investment manager that exercises discretion over $100 million or more in qualifying US equity securities must file a 13F with the SEC each quarter. This includes hedge funds, mutual funds, pension funds, bank trust departments, insurance companies, and endowments.

Managers below the $100M threshold are not required to file and therefore do not appear in public 13F data. Some well-known investors — particularly those running small, concentrated funds — may not file at all.

What is and isn't disclosed?

Understanding the scope of a 13F is essential for interpreting the data correctly.

What is disclosed: Long positions in US-listed equities, including common stock, ETFs, convertible notes, and equity options (PUT and CALL contracts).

What is not disclosed: Short positions, bonds and fixed income, foreign-listed stocks, private equity, real estate, cash, and currencies. A fund's 13F can therefore look very different from its actual portfolio — a fund that is net short US equities will still show only its long book.

How to use this data

13F data is most useful as a starting point for research — not as a real-time signal. Because filings are delayed by up to 45 days, a position you see reported may have already been sold by the time you read it.

The most reliable signal in 13F data is long-term conviction. A position that appears consistently across multiple quarters, growing in size, is more likely to reflect genuine long-term conviction than a position that appeared once. Use the quarter history on each fund and stock page to identify these patterns.

Consensus signals — stocks that many funds are buying or selling simultaneously — are also worth attention. Our Consensus Buys & Sells page surfaces these each quarter. For deep dives, the Fund Comparison tool shows which stocks multiple specific managers hold in common.

Which hedge funds own a specific stock?

Every stock tracked on 13FAI has a dedicated ownership page showing all funds holding that position, their share counts, portfolio weights, and quarter-over-quarter changes. For example, to see which hedge funds own Apple: AAPL hedge fund ownership. The page also shows aggregate ownership trends over 8 quarters and highlights new positions, increases, and exits.

You can also use the search bar on any page — type a ticker or company name and select the stock result to go directly to its ownership page.

How do I find a specific manager's holdings?

Each fund has a dedicated holdings page showing its full portfolio by quarter. You can find any fund from the homepage by searching the manager's name or fund name. For the most followed managers, 13FAI also has dedicated bio pages with biography, investment philosophy, notable trades, and a live holdings preview — see the Manager Bios directory.

Some examples: Warren Buffett, Stanley Druckenmiller, Bill Ackman, Michael Burry.

What stocks do multiple hedge funds own in common?

13FAI offers three tools for this. The Top Holdings page ranks stocks by aggregate hedge fund ownership value and shows how many tracked funds hold each stock. The Consensus Buys & Sells page shows which stocks the most funds are buying or selling this quarter. The Fund Comparison tool lets you select up to 5 specific funds and see exactly which holdings they share.

When are 13F filings due?

13F filings are due within 45 days of each quarter end date:

Q1 (March 31) → due by mid-May
Q2 (June 30) → due by mid-August
Q3 (September 30) → due by mid-November
Q4 (December 31) → due by mid-February

Different funds file at different times within this 45-day window — some file on day 1, others wait until the deadline. The 13F Filing Calendar shows the most recent filed date and next expected filing date for every tracked fund.

Which hedge funds have the most concentrated portfolios?

Concentration varies widely across the funds tracked on 13FAI. Highly concentrated funds — those with a large share of assets in just a few positions — include Pershing Square Capital Management, Scion Asset Management, RV Capital, and Greenlea Lane Capital. These funds typically hold fewer than 15 positions with their top 3 holdings representing 50% or more of the portfolio.

More diversified funds like Causeway Capital, Ariel Investments, and Dodge & Cox typically hold 30–80 positions with lower individual weights. Each fund page shows the top 3 and top 5 holding weights in the insights summary, making it easy to assess concentration at a glance.

What do the shares vs prior quarter and prior year columns mean?

The Shares vs Prior Quarter column shows the percentage change in the number of shares held compared to the immediately preceding quarter. A value of +25% means the fund bought 25% more shares than it held last quarter. A value of -50% means it sold half its position. NEW indicates the position did not exist in the prior quarter. EXITED means the position was held last quarter but is gone now.

The Shares vs Prior Year column compares to the same quarter one year ago — Q1 2026 vs Q1 2025, for example. This smooths out short-term noise and shows longer-term conviction. A position that has grown 200% year-over-year indicates sustained accumulation over multiple quarters.

What is a Form 4 filing?

A Form 4 is an SEC filing that corporate insiders — officers, directors, and owners of more than 10% of a company's shares — must submit within two business days of any transaction in their company's stock. It discloses the transaction type, number of shares, price paid, and the insider's total ownership after the trade.

Form 4 filings are public record on SEC EDGAR. 13FAI tracks open market purchases and sales across the top 100 S&P 500 companies and displays them alongside hedge fund holdings data on each stock page.

What does it mean when a CEO buys stock?

An open market purchase by a CEO or other executive is widely considered a bullish signal. Unlike awards or option exercises — which are automatic or contractual — an open market purchase means the insider spent their own money at prevailing market prices. It signals genuine personal conviction that the stock is undervalued.

The signal is strongest when the purchase is large relative to the insider's existing holdings, multiple insiders buy simultaneously, or the purchase follows a period of significant stock price weakness. A single small purchase by a minor director carries less weight than a major purchase by the CEO.

How is insider trading data different from 13F hedge fund data?

13F filings are filed quarterly by institutional investors managing over $100M. They show the fund's entire equity portfolio as a snapshot at quarter end — what they own, how much, and how it changed vs the prior quarter.

Form 4 insider filings are filed within 2 business days of any transaction by corporate insiders. They show individual trades by people with direct knowledge of the company's operations and prospects.

13F data tells you what sophisticated outside investors own. Form 4 data tells you what the people running the company are personally doing with their own money. Both are valuable independently — and especially powerful when they point in the same direction.

Which insider transactions are worth following?

Only two transaction types represent genuine discretionary decisions worth tracking.

Open market purchases (code P) — the insider bought shares at market price with their own money. This is the strongest bullish signal and the one most associated with positive forward returns.

Open market sales (code S) — the insider sold shares at market price. This can indicate bearishness but often reflects personal financial planning, diversification, or pre-scheduled selling plans (10b5-1 plans), so it carries less weight than a purchase.

Transactions to ignore: stock awards (A), option exercises (M), and tax withholding sales (F) are mechanical or contractual and tell you nothing about the insider's view of the stock. 13FAI filters these out and shows only open market buys and sells.

What does it mean when hedge funds and insiders are both buying the same stock?

This convergence is one of the most compelling signals in public market data. Institutional investors bring rigorous external analysis — studying financials, competitive dynamics, and valuation from the outside. Corporate insiders bring direct internal knowledge — they know the pipeline, customer relationships, and operational reality better than any outside analyst.

When both groups are independently increasing their exposure to the same stock, the alignment of external analysis and internal conviction is historically associated with strong forward performance. It narrows the field of stocks worth researching further.

Use 13FAI's stock pages to see both data points side by side — hedge fund holdings and recent insider transactions in one view. You can also see consensus activity across all tracked stocks on the Insider Trading page.

What is a congressional trade disclosure?

Members of Congress and their spouses are required to disclose personal stock trades through Periodic Transaction Reports (PTRs). These reports must be filed within 30 days of a transaction and are made publicly available through the House and Senate financial disclosure systems.

13FAI tracks PTR filings from the most actively trading members of the House of Representatives, displaying each trade with the asset, transaction type, date, and amount range disclosed in the filing.

What is the STOCK Act?

The Stop Trading on Congressional Knowledge (STOCK) Act was passed in 2012 and makes it illegal for members of Congress to trade securities based on material non-public information obtained through their official duties. It also established the PTR filing requirement, mandating public disclosure of trades within 30 days.

Despite the law, enforcement has been limited. Late filings are common and typically result in small nominal fines. No member has been prosecuted under the STOCK Act to date, though the disclosures themselves provide useful transparency into congressional trading activity.

How are congressional trades different from insider trades?

Corporate insider trades (Form 4) are filed by executives and directors of public companies who may have access to material non-public information about that specific company. Their trades carry strong informational weight because they know the company's financials, pipeline, and business health better than any outside observer.

Congressional trades (PTRs) are filed by elected officials who may have advance knowledge of legislation, regulatory actions, government contracts, or macroeconomic policy — information that could affect broad sectors or specific companies. The informational edge, if any, is different in nature: it relates to policy rather than company-specific operations.

Both are public disclosures worth monitoring, but they carry different informational implications. Neither should be treated as a reliable trading signal without additional research.

Are congressional trades worth following?

The academic evidence is mixed. Some studies have found that congressional portfolios historically outperformed market benchmarks, particularly in sectors subject to regulation or government spending. Others find no statistically significant edge after controlling for market exposure.

A few practical considerations: amount ranges are imprecise (you know a trade was between ,001 and 5,000, but not the exact size); filings can be up to 30 days late; some members trade frequently in broad ETFs that carry no informational signal; and active traders like Josh Gottheimer make thousands of trades per year that would be impractical to follow.

The most useful application is monitoring concentrated single-stock trades in sectors where the member has committee oversight or known policy influence — rather than trying to mirror their entire portfolio mechanically.