Every market-moving event reaches the public as a regulatory filing first. These explainers cover the forms behind the headlines — what each one is, who files it, on what deadline, and how to read it. Written and maintained by Gunpowder Editorial; the same forms are scored daily by our analysis pipeline.
An 8-K is the SEC's current report — the form US public companies use to disclose material events between scheduled quarterly reports. Most events must be reported within four business days. Earnings releases, executive departures, mergers, and bankruptcies all reach the market first as 8-K filings on SEC EDGAR.
A 10-K is a company's audited annual report filed with the SEC; a 10-Q is the unaudited quarterly version, filed three times a year. The 10-K is deeper — full business description, risk factors, and audited financials — while the 10-Q updates results and material changes between annual reports.
Form 20-F is the annual report that foreign private issuers — non-US companies whose shares trade on US exchanges — file with the SEC. It is the international counterpart to a domestic company's 10-K, due within four months of fiscal year-end, and foreign issuers file it instead of quarterly 10-Qs.
A Form 4 is the SEC filing corporate insiders — officers, directors, and shareholders owning more than 10% — must submit within two business days of buying or selling their company's stock. Filed under Section 16, Form 4s are the primary public record of insider trading activity.
Schedules 13D and 13G are SEC filings required when an investor's stake crosses 5% of a public company's voting shares. A 13D is the long form for investors with control intent and is due within five business days; a 13G is the short form for passive and institutional investors.
A Form 13F is the quarterly report that institutional investment managers with at least $100 million in US-listed securities must file with the SEC, disclosing their long equity holdings. Filed within 45 days of each quarter's end, 13Fs are the public's main window into what hedge funds and other large investors own.
A DEF 14A is a definitive proxy statement — the document a public company must send shareholders before they vote at a shareholder meeting. It discloses board nominees, executive compensation, auditor selection, and shareholder proposals, making it the primary public record of how a company is governed and paid.
A Form 425 is how companies file the written communications they make about a merger or acquisition — press releases, investor decks, and similar materials — when stock is being offered in the deal. Required by Rule 425 under the Securities Act, these filings keep M&A communications public from the first announcement onward.
An S-1 is the registration statement a company files with the SEC to offer shares to the public — the filing behind nearly every US IPO. It contains the prospectus: the business model, risk factors, use of proceeds, and audited financials investors see before the shares ever trade.
Form S-3 is the SEC's short-form registration statement, used by established public companies to register new securities — often a shelf registration that lets them sell stock or debt over time. Because S-3 filers can incorporate their existing SEC reports by reference, it is far faster and lighter than the S-1 used for IPOs.
Insider cluster buying is when several corporate insiders at the same company — executives, directors, or large owners — buy its stock within a short window. Because multiple insiders are acting on the same conviction at once, cluster buys are generally read as a stronger signal than any single insider purchase.
Smart-money convergence is when two or three independent groups of well-informed investors — members of Congress, superinvestor funds, and corporate insiders — buy or sell the same stock in the same direction within a short window, typically 45 days. It is a consensus signal no single source reveals on its own.
Superinvestor tracking — sometimes called whale watching — means following the quarterly 13F filings of a curated set of legendary fund managers to see which stocks they bought, added, trimmed, or exited. The signal lives in the quarter-over-quarter changes and where multiple managers agree, not in any single holding.
The STOCK Act (Stop Trading on Congressional Knowledge Act of 2012) is a U.S. law that bars members of Congress from trading on non-public information and requires them to publicly disclose securities trades over $1,000 within 45 days. Those disclosures are what make congressional stock-trade tracking possible.