Quick Answer: An 8-K is the SEC form companies file within four business days of a material event: an acquisition, an executive departure, a bankruptcy, a cybersecurity incident, and more. To read one in five minutes, skip straight to the "Item" number at the top (it tells you what kind of event this is), read the one or two paragraph description, and check the exhibits for the actual press release or presentation. Tools like NowNews' Reports module summarize the Item type and flag whether it's historically a bullish or bearish trigger before you finish your coffee.
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Why the 8-K matters more than people think
Most retail investors know the 10-K (annual report) and the 10-Q (quarterly report). Far fewer pay attention to the 8-K, even though it's the filing most likely to move a stock price today, not next quarter.
The 8-K exists because the SEC doesn't want investors waiting until the next scheduled report to learn about something material. Any US public company must disclose specified events within four business days of the event occurring, not four days after they feel like sharing it.
The stakes are real. Researchers analyzing 8-K filings found that abnormal returns and volume spikes cluster tightly around the filing date with an average three-day return around the filing date of roughly +2.3% and elevated trading volume when filings arrive on time, and a notably worse reaction when the same disclosures arrive late. Late filings read as a signal in themselves, and NYSE and Nasdaq can even require a company to publicly announce that it missed a deadline.
What an 8-K actually is
An 8-K, formally the "Current Report," is a disclosure companies must submit any time a specific list of material events happens between their regular quarterly and annual filings. Think of it as the SEC's version of breaking news, filed directly by the company rather than reported by a journalist.
The SEC defines 33 separate event categories that trigger a mandatory 8-K, and once one of those events occurs, the company has four business days to disclose it. That's a wide net: everything from a new CEO to a bankruptcy filing to a cyberattack can trigger the form.
8-K vs 10-K vs 10-Q: the difference that trips people up
| Filing | What it covers | When it's filed | What to look for |
|---|---|---|---|
| 10-K | Full annual business and financial review | Once a year | Risk factors, full financials, MD&A |
| 10-Q | Condensed quarterly financials | Three times a year | Quarter-over-quarter trends |
| 8-K | A single material event | Within 4 business days of the event | Item number, exhibits, dates |
The 10-K and 10-Q are scheduled and predictable. The 8-K is event-driven: it can show up on a Tuesday afternoon, a Friday at 4:05pm (a favorite slot for bad news, more on that below), or in the middle of an earnings season with zero warning.
The five-minute reading method
You don't need to read every paragraph. Here's the order that gets you the signal fastest.
Step 1: Read the Item number first (30 seconds)
Every 8-K opens with one or more "Item" codes. This single number tells you almost everything about what kind of news you're dealing with before you read a word of prose. The most common ones worth memorizing:
- Item 1.01 — Entry into a material definitive agreement (new contract, partnership, credit facility)
- Item 2.01 — Completion of acquisition or disposition of assets
- Item 2.02 — Results of operations (often accompanies earnings)
- Item 3.02 — Unregistered sales of equity securities (dilution alert)
- Item 4.01 — Changes in the company's accountant or auditor
- Item 5.02 — Departure or appointment of directors/executives
- Item 7.01 — Regulation FD disclosure (a catch-all for material info shared broadly)
- Item 8.01 — Other events (a flexible bucket, often used for voluntary disclosures)
- Item 1.05 — Material cybersecurity incident (added in December 2023)
- Item 9.01 — Financial statements and exhibits (the attachments)
If you only learn five of these, learn 1.01, 2.02, 5.02, 1.05, and 8.01. They cover the vast majority of market-moving filings.
Step 2: Read the one or two paragraph body (90 seconds)
Unlike a 10-K, the body of an 8-K is usually short: a paragraph or two describing what happened, sometimes with a date, a dollar figure, or a name. There's no fluff to wade through because the form itself doesn't allow for it. If it reads long, it's often because multiple Items are being disclosed together, which is common around earnings.
Step 3: Check the exhibits (2 minutes)
This is where the actual substance usually lives. Item 9.01 lists attached exhibits, most commonly:
- EX-99.1: Often the press release itself, in plain language
- Investor presentation slides (frequently used for cybersecurity and M&A disclosures)
- The actual agreement or amendment being disclosed
If the filing feels vague, the exhibit is almost always where the real numbers and quotes are.
Step 4: Note the filing date and time (30 seconds)
This matters more than most people realize. Companies have discretion over when during the day and week they file, and research on strategic disclosure timing finds that unfavorable news is more likely to be filed when market attention is lower, specifically just after markets close, on Fridays, and especially after markets close on Fridays. A 4:05pm Friday 8-K is a pattern worth recognizing on sight.
Step 5: Decide if it needs a deeper read (1 minute)
Not every 8-K needs full analysis. A routine Item 5.02 announcing a board member's retirement rarely moves anything. But Item 2.01 (completed acquisition), Item 1.05 (cyber incident), Item 3.02 (dilutive share sale), or an unscheduled Item 2.02 (results outside the normal earnings calendar) usually deserve five more minutes with the actual exhibit.
What tends to move the stock, and what doesn't
Academic work on 8-K price reactions is a useful reality check against instinct. One large-sample study found a mean abnormal return across all 8-K filings of just 0.0361%, with roughly as many filings producing a positive reaction as a negative one, and a standard deviation around 4% in either direction. In plain terms: most 8-Ks, taken individually, are noise. The market has already priced in a lot of what gets disclosed, or the event itself is genuinely minor (a routine officer appointment, a technical amendment).
The filings that do move price sharply tend to share three traits: they're unscheduled (not part of the normal earnings rhythm), they involve a change in what the company is worth or owes (an acquisition, a dilution, a bankruptcy), or they involve a factor the market didn't already suspect. A recent review of cybersecurity-incident 8-Ks under Item 1.05 found the category still developing fast, noting that the SEC's cybersecurity disclosure rule, effective since December 18, 2023, requires public companies to disclose a material cyber incident on Form 8-K within four business days of determining materiality, and that filing must cover the incident's nature, scope, timing, and likely impact. That four-day clock, combined with how binary "material vs. not material" judgment calls can be, is exactly why these filings tend to produce outsized reactions when they land.
Common mistakes when reading 8-Ks
- Treating every 8-K as equally important. Most are administrative. Filter by Item number first.
- Ignoring the exhibits. The body text can be legally cautious to the point of vagueness; the press release exhibit usually isn't.
- Missing the timing pattern. A Friday-afternoon filing is a data point, not a coincidence.
- Confusing 8-K earnings filings with the earnings call itself. Item 2.02 often just attaches the press release; the color and guidance usually come later on the call or in a slide deck exhibit.
- Assuming the market hasn't already moved. By the time you read a same-day 8-K, algorithmic readers have often already parsed it in milliseconds. Your edge is usually in interpretation and follow-through, not speed.
How AI tools like NowNews speed this up
Reading 8-Ks manually across a watchlist of even 15-20 names gets tedious fast, especially during earnings season when they arrive in clusters. NowNews' Reports tool pulls SEC filings including 8-Ks and lets you query them directly through an AI chat, with quick actions like Summarize, Key Metrics, and Compare Docs so you're not scanning legal boilerplate line by line. Its Impact Feed also flags high-impact filings across your portfolio automatically, tagging the likely direction (bullish or bearish) and estimated affected assets so the ones worth five minutes of your attention surface on their own instead of getting buried in a feed of routine officer changes.
That doesn't replace judgment. Platforms like AlphaSense and Bloomberg Terminal offer deep filing search for institutional users at a much higher price point, and Koyfin covers filings alongside broader market data for a more casual workflow. What NowNews focuses on is compressing the read-and-decide loop for individual filings so a retail trader or small fund analyst isn't spending twenty minutes on something that should take five.
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FAQ
What is an 8-K filing in simple terms?
It's a report a public company must file with the SEC within four business days whenever a specific list of material events happens, such as an acquisition, executive change, bankruptcy, or cybersecurity incident.
How is an 8-K different from a 10-K?
A 10-K is a comprehensive annual report covering a full fiscal year of financials and risk factors. An 8-K is a short, event-triggered disclosure filed whenever something material happens, which can be any day of the year.
How many days does a company have to file an 8-K?
Four business days from the date the triggering event occurs, or in some cases from the date the company determines the event is material, such as with cybersecurity incidents under Item 1.05.
What happens if a company files an 8-K late?
Late 8-Ks tend to draw more negative investor attention than on-time ones covering similar news, exchanges like NYSE and Nasdaq can require a public statement acknowledging the delay, and the SEC can pursue administrative action in serious cases.
Which 8-K items are worth paying closest attention to?
Item 1.01 (material agreements), Item 2.01 (completed acquisitions), Item 2.02 (unscheduled results), Item 3.02 (dilutive share sales), Item 5.02 (executive changes), Item 1.05 (cybersecurity incidents), and Item 8.01 (other material events) cover most of what moves prices.
Do all 8-K filings move the stock price?
No. Most individual 8-Ks produce a near-zero average price reaction because a large share of disclosures are routine. The filings that move price sharply tend to be unscheduled, financially significant, or genuinely unexpected by the market.
Why do companies file 8-Ks late on Fridays?
Research on disclosure timing finds companies do have discretion over filing time, and unfavorable news is statistically more likely to be filed when market attention is lowest, which often means after the close on a Friday.
Can I get 8-K filings summarized automatically?
Yes. Tools like NowNews' Reports module and general SEC filing trackers can surface new 8-Ks as they hit EDGAR and generate a plain-language summary, though for judgment calls on materiality and likely price impact you'll still want to read the exhibit yourself.
Where can I find a company's 8-K filings?
Directly on SEC EDGAR under the company's filing history, through your broker's research tools, or through platforms like NowNews, Bloomberg Terminal, or AlphaSense that index and summarize filings as they're published.
Is an 8-K the same as a press release?
Not exactly. The 8-K is the legal disclosure document; the press release is often attached to it as an exhibit (commonly labeled EX-99.1) and tends to contain the plain-language version of the same news.
Bottom line
An 8-K rewards a fast, structured read far more than a slow, exhaustive one. Learn the handful of Item numbers that actually matter, go straight to the exhibit for substance, and pay attention to when a filing lands, not just what it says. Do that consistently across a watchlist and five minutes per filing is genuinely enough.
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Last reviewed: July 2026.