This glossary covers the terms you will encounter most often when working with insider trading data, superinvestor 13F filings, and congressional stock disclosures. Each definition is written to be practical rather than technical — focused on what the term means for investment research rather than its precise legal definition.
Terms are organized alphabetically within each section.
Insider Trading & SEC Filings
Beneficial Owner
A person who has the economic benefits of ownership of a security, even if legal title is held by someone else. For SEC reporting purposes, beneficial ownership includes shares held in trust, by a spouse, or through other arrangements where the reporting person has investment control. A director whose spouse holds shares must report those shares as beneficially owned.
Cluster Buying
A pattern where three or more company insiders make open-market stock purchases within a short window of time — typically seven to thirty days. Cluster buying is widely considered one of the strongest buy signals available in insider trading data because it represents the convergence of independent judgment from multiple people with deep knowledge of the same business. See our full guide to insider cluster buying.
CUSIP
A nine-character alphanumeric code assigned to every registered security in the United States and Canada. CUSIP stands for Committee on Uniform Security Identification Procedures. Raw 13F filings report positions using CUSIP numbers rather than ticker symbols, which makes them difficult to read without conversion software.
Edgar (EDGAR)
The SEC's Electronic Data Gathering, Analysis, and Retrieval system. EDGAR is the public database where all mandatory SEC filings are published, including Form 3, Form 4, Form 5, and 13F filings. Available free at sec.gov/cgi-bin/browse-edgar.
Form 3
The initial ownership disclosure filed by a person when they first become a company insider — an officer, director, or 10% beneficial owner. Form 3 must be filed within 10 calendar days of becoming an insider and shows the person's existing ownership position at that date. It establishes the baseline from which all subsequent Form 4 changes are measured. See our guide to Form 3 vs Form 4 vs Form 5.
Form 4
The primary ongoing insider ownership disclosure, filed whenever an insider's beneficial ownership changes for any reason. Form 4 must be filed within two business days of any transaction. It is the foundation of all insider trading research and the source of the open-market purchase signals that investors track most closely. See our complete guide to what SEC Form 4 is.
Form 5
An annual catch-up filing that covers transactions exempt from immediate Form 4 reporting — primarily very small transactions under $10,000 — or transactions that were missed during the year. Form 5 is due 45 days after a company's fiscal year end. It rarely contains investment-significant information given its annual timing and narrow scope.
Form 13F / 13F-HR
A quarterly disclosure required of institutional investment managers with $100 million or more in qualifying assets under management. Form 13F lists every long equity position the manager held at the end of the quarter, including the number of shares and market value of each position. It is the primary source of superinvestor portfolio data. See our full guide to what a 13F filing is.
13F Season
The informal term for the period following each quarterly 13F filing deadline — approximately mid-February, mid-May, mid-August, and mid-November — during which institutional investor portfolio disclosures become available. It is the most information-dense period of the quarter for investors who track superinvestor holdings. See our guide to what 13F season is.
Insider
For SEC reporting purposes, an insider is any officer, director, or beneficial owner of more than 10% of any class of a company's registered equity securities. Being an insider is not the same as committing insider trading — the term simply describes people with significant ties to a company who are subject to ownership reporting requirements.
Insider Trading (Legal)
The legal activity of company insiders — officers, directors, and major shareholders — buying or selling their own company's stock, provided the trades are disclosed on time and not based on material non-public information. The vast majority of transactions reported on Form 4 are legal insider trading.
Insider Trading (Illegal)
Trading in a security based on material non-public information obtained in breach of a duty of trust or confidence. Illegal insider trading carries civil and criminal penalties including fines and imprisonment. The STOCK Act extended these prohibitions explicitly to members of Congress and their staff.
Material Non-Public Information (MNPI)
Information that (1) would be considered important by a reasonable investor in deciding whether to buy or sell a security and (2) has not been made available to the general public. Insider trading on MNPI is illegal. The key challenge in enforcement is determining what constitutes material information and whether it was truly non-public at the time of trading.
Open Market Purchase
A voluntary purchase of shares on the open market at prevailing market prices, using personal funds. Open market purchases by company insiders — identified by transaction code P on Form 4 — are the most meaningful signal in insider trading data because they represent a discretionary financial commitment with no alternative explanation other than the belief that the stock will appreciate. Contrasted with option exercises, equity grants, and other non-discretionary transaction types.
Rule 10b5-1 Plan
A pre-scheduled trading arrangement that allows corporate insiders to buy or sell shares at predetermined future dates or price points, established during a period when the insider is not in possession of material non-public information. Sales made under a 10b5-1 plan are disclosed on Form 4 with a footnote identifying the plan and its adoption date. Plan-based sales carry significantly less directional signal than discretionary sales. See our full guide to what a 10b5-1 plan is.
Section 16
The section of the Securities Exchange Act of 1934 that requires officers, directors, and 10% beneficial owners of public companies to report their ownership and changes in ownership to the SEC. Section 16 also prohibits short-swing profits — buying and selling the same company's stock within a six-month window.
Short-Swing Profit Rule
A provision of Section 16 that requires insiders to disgorge any profit earned from buying and selling (or selling and buying) their company's stock within any six-month period. The rule applies automatically, regardless of whether the insider possessed non-public information. Profits subject to the short-swing rule can be recovered by the company or by a shareholder suing on the company's behalf.
Transaction Code
A single-letter code on Form 4 that identifies the type of transaction being reported. The most important codes for investment research: P (open-market purchase — the primary buy signal), S (open-market sale — ambiguous), M (derivative exercise — mechanical), F (tax withholding on vesting — automatic), A (grant or award — compensation). Always check the transaction code before interpreting any Form 4 filing.
Congressional Trading & STOCK Act
13D / 13G Filing
Filings required when an investor acquires beneficial ownership of more than 5% of any class of a public company's registered equity securities. Schedule 13D is required when the investor has or plans to have an active role in influencing company management. Schedule 13G is available for passive investors. These filings must be made within 10 days of crossing the 5% threshold and updated promptly when positions change significantly.
Blind Trust
A trust arrangement in which the beneficiary has no knowledge of or control over the trust's investments. Members of Congress who place their assets in a properly structured blind trust are generally exempt from trading disclosure requirements, because the investment decisions are made independently by the trustee. Critics argue that blind trusts are underused and that the STOCK Act should require them.
Periodic Transaction Report (PTR)
The disclosure form that members of Congress, their spouses, and dependent children must file when making a stock transaction of $1,000 or more. PTRs must be filed within 45 days of the transaction and include the asset traded, transaction type, value range, and date. PTRs are the source data for all congressional trade tracking platforms. See our guide to what the STOCK Act is.
STOCK Act
The Stop Trading on Congressional Knowledge Act, signed into law in April 2012. The STOCK Act explicitly extended insider trading prohibitions to members of Congress and federal employees and created the mandatory PTR disclosure system. It also originally required online disclosure within one business day — a provision that was quietly removed by amendment shortly after enactment, reverting to the 45-day paper filing window. See our full guide to what the STOCK Act is.
TRUST in Congress Act
A proposed (but not yet passed) bipartisan bill that would require members of Congress and their spouses to either divest individual stock holdings or place them in a qualified blind trust within 180 days of taking office. If enacted, it would effectively end individual stock trading by active members of Congress. The bill has been reintroduced multiple times but has not advanced to a floor vote.
Superinvestors & Institutional Investing
Assets Under Management (AUM)
The total market value of assets that an investment manager oversees on behalf of clients. AUM is the primary threshold determining whether a manager must file quarterly 13F disclosures — the current threshold is $100 million in Section 13(f) securities.
Clone Investing
An investment strategy that involves replicating the disclosed portfolio of a tracked superinvestor, using 13F filings as the source of stock selection. Also called coattail investing. The 45-day disclosure lag and the inability to observe short positions, options strategies, and cash levels mean that clone investing always provides an incomplete picture. See our guide on how to build an investment watchlist using 13F data.
Consensus Portfolio
The set of stocks held by the greatest number of tracked superinvestors simultaneously. A consensus holding — appearing in multiple independent superinvestor portfolios — suggests that several rigorous analytical processes have independently concluded the stock is worth owning. Consensus portfolios are a useful starting point for generating research ideas.
Guru
An informal term, popularized by platforms like GuruFocus, for a highly regarded investment manager with a well-documented track record. Used interchangeably with "superinvestor" in most research contexts.
High Conviction Position
A position that represents a significant percentage of an investor's total portfolio, indicating that they have concentrated capital in the idea relative to other holdings. A high-conviction position for a concentrated manager might be 10–20% of the portfolio. High-conviction positions carry stronger signals than token positions representing less than 1% of assets.
Institutional Investment Manager
Any entity that exercises investment discretion over accounts totaling $100 million or more in Section 13(f) securities. Institutional managers are required to file quarterly 13F disclosures with the SEC. The category includes hedge funds, mutual funds, pension funds, endowments, insurance companies, and bank trust departments.
Portfolio Turnover
The rate at which holdings within a portfolio change over a given period, typically measured annually. Low-turnover investors — those who buy and hold for years — are generally more valuable to follow through 13F data because their disclosed positions are more likely to still be held by the time the filing becomes public. High-turnover investors may have significantly repositioned by the time their quarterly filing is visible.
Section 13(f) Securities
The specific category of U.S.-listed securities covered by the 13F reporting requirement, including exchange-listed equity securities, shares of closed-end funds, and certain exchange-traded options. The 13F filing requirement applies specifically to Section 13(f) securities — international stocks, bonds, private investments, and derivatives are generally not covered.
Superinvestor
An investor with an exceptional long-term track record, significant assets under management, and a clearly defined investment philosophy. The term is commonly used to describe managers whose 13F filings attract widespread attention — figures like Warren Buffett, Seth Klarman, Bill Ackman, Michael Burry, David Tepper, and similar managers with documented records of outperformance over multiple decades.
General Market Terms
Abnormal Return
A return on an investment that differs from the expected return based on a benchmark or risk model. In insider trading research, abnormal returns measure the performance of stocks following insider purchases or sales compared to the market as a whole — adjusting for factors like market cap, sector, and general market movements.
Beneficial Ownership
Ownership that provides the economic benefits of a security — dividends, voting rights, capital appreciation — even if the legal title is held by another party. Beneficial ownership is broader than direct ownership and includes shares held through trusts, spouses, dependent children, and certain nominee arrangements.
Conviction
In investment management, the degree of confidence an investor has in a particular investment thesis, typically expressed through position sizing. High-conviction positions are large relative to the portfolio; low-conviction positions are small. Tracking conviction — both through position size and through changes in position size over time — is an important part of interpreting superinvestor portfolio data.
Intrinsic Value
An estimate of a company's true underlying value based on its fundamental characteristics — earnings power, growth prospects, competitive position, and balance sheet strength — independent of its current market price. Value investing is fundamentally about identifying securities trading at significant discounts to their intrinsic value and waiting for the market to recognize that value over time.
Margin of Safety
A concept popularized by Benjamin Graham and central to value investing. The margin of safety is the discount between an asset's estimated intrinsic value and its current market price. Buying with a wide margin of safety provides protection against errors in the intrinsic value estimate and against unforeseen adverse developments. Seth Klarman's book Margin of Safety is one of the most sought-after texts in value investing.
Smart Money
An informal term for investors or institutions believed to have superior information or analytical capabilities — corporate insiders, long-term superinvestors, and in some interpretations, politically connected traders. "Following the smart money" refers to strategies that use public disclosure data to identify and track positions taken by these sophisticated investors.
Value Investing
An investment philosophy focused on buying securities that appear underpriced relative to their fundamental value, with the expectation that the price will eventually reflect that value. Value investors typically look for companies with low price-to-earnings ratios, strong balance sheets, durable competitive advantages, and honest, capable management. Warren Buffett, Seth Klarman, and most of the superinvestors tracked on this platform are broadly categorized as value investors.