How to Track SEC Filings and Insider Trades (and What Each Form Actually Means)

Public companies are required to tell the truth in writing, on a schedule, to the SEC. That paper trail is the single best free source of signal on a business: how it is performing, what just changed, and whether the people who run it are buying or selling their own stock.

The problem is the raw system. SEC EDGAR holds millions of documents behind form codes like 10-K, 8-K, and Form 4. If you do not already know what those mean, the firehose is useless.

Here is the practical version: what each filing type tells you, how to read insider activity, and a free live feed to follow it across the largest public companies.

The filings that matter, in plain language

You do not need to know all 100-plus form types. Five buckets cover almost everything worth watching.

10-K: the annual report

The audited, once-a-year, full picture. Financial statements, risk factors, and a plain-language review of the business from management. If you only read one document about a company, read this. It is long on purpose. The risk factors section alone often tells you more than any earnings headline.

10-Q: the quarterly report

The unaudited update between annual reports, filed three times a year. This is the fastest read on whether revenue, margins, and cash are trending the right way. Compare it to the same quarter last year, not the previous quarter, so seasonality does not fool you.

8-K: the major event

Filed on demand whenever something material happens: earnings releases, executive departures, acquisitions, big contracts, or restructurings. An 8-K is the company saying "you should know this before our next scheduled report." When you see a cluster of 8-Ks, something is going on.

Form 4: the insider trade

Filed within two business days when a director, officer, or large owner buys or sells the company's stock. This is the closest thing to watching how insiders themselves are positioned. More on reading these below.

S-1 and 13D/13G: registrations and ownership stakes

An S-1 is a private company registering to go public, the first real look at its financials before an IPO. A 13D or 13G is filed when an investor crosses 5% ownership: 13D signals an active or activist stake, 13G a passive one. Both are worth a look when a new large holder appears.

How to actually read insider trades

Form 4 is the most misunderstood filing, so it is worth slowing down.

When an insider transacts, the Form 4 reports the person, the date, a transaction code, the number of shares, and the price. The two codes you will see most:

• P (purchase) and S (sale) are open-market trades. An open-market purchase is the strongest signal, because the insider is spending their own money at the current price with no obligation to do so.
• M, A, and F relate to options, grants, and tax withholding. A "sale" that is really an automatic tax withholding on a vesting grant is not the same as an executive choosing to sell. Read the footnotes.

A few rules of thumb:

• Open-market buys by multiple insiders at once are rare and meaningful.
• Routine selling under a pre-arranged 10b5-1 plan is normal and usually not a signal. The Form 4 footnotes will say if a plan was in place.
• One insider's trade is noise. A pattern across several insiders is information.

The point is not to copy insiders. It is to notice when the people with the most information are doing something out of the ordinary.

A free live feed for all of it

Reading one filing is easy. Keeping up with the flow across hundreds of companies is the hard part. That is the gap we built for.

The Developers Digest markets section indexes SEC filings across the largest public companies and links every document straight back to its source on SEC EDGAR. Two views do most of the work:

• The latest filings feed shows the newest disclosures across all tracked companies, newest first, with a NEW badge on anything filed in the last day. Filter to annual reports, quarterly reports, major events, or insider trades with one tap.
• Each company has its own filings page with the full history, filters by type and year, and a jump-to-peers strip so you can hop from one company to its competitors. For example, Tesla's page links straight to Ford, GM, Rivian, and the rest of the automakers.

Every row opens the original filing on SEC EDGAR in a new tab, so you are always one click from the primary source. We index and organize; the SEC remains the system of record.

Where to go deeper

• SEC EDGAR full-text search for searching across filings by keyword, back to 2001.
• The SEC's own guide to reading a 10-K is short and genuinely useful.
• SEC Forms list if you hit a form code not covered here.

FAQ

What are SEC filings?

SEC filings are documents that public companies are legally required to submit to the U.S. Securities and Exchange Commission. They cover financial results, major corporate events, insider trades, and ownership changes, and they are the primary public record of how a company is performing.

How do I track insider trading?

Watch Form 4 filings. Each one reports a director, officer, or major holder buying or selling shares within two business days of the trade. Focus on open-market purchases (code P), look for patterns across multiple insiders, and read the footnotes to separate real decisions from routine plan sales and tax withholding.

Are SEC filings free to access?

Yes. All filings are free on SEC EDGAR, the SEC's official electronic filing system. Tools like the Developers Digest markets feed organize that public data and link back to the original documents.

What is the difference between a 10-K and a 10-Q?

A 10-K is the audited annual report with complete financial statements and risk factors. A 10-Q is an unaudited quarterly update filed three times a year. The 10-K is more thorough; the 10-Q is more timely.