Insider Trading Blackout Periods & Trading Windows Explained

Insiders don’t trade whenever they feel like it. A two-layer calendar of restrictions determines when they can legally buy or sell—and understanding that calendar changes how you should read every Form 4 open-market purchase.

Most coverage of insider trading filings focuses on transaction codes and dollar sizes—how much did the CEO buy, how many shares did the CFO sell. What that coverage misses is the invisible calendar underneath every trade. Corporate insiders operate inside a structured system of trading restrictions that determines not just what they can buy or sell, but whenthey’re even allowed to try. Understanding that calendar is what separates a high-conviction insider trading blackout period signal from background noise.

Two separate rule systems layer on top of each other to create this calendar: company policy (quarterly earnings blackouts, event-driven restrictions, pre-clearance requirements) and federal law (Regulation BTR, which governs trading during pension plan lockouts). A 2022 SEC rule then changed the picture by requiring every public company to publish its insider trading policy as a searchable exhibit—making the calendar visible to the public for the first time.

The Two-Layer Trading Calendar Every Insider Operates Under

The phrase “insider trading blackout period” gets used loosely, but there are actually two distinct legal frameworks creating these restrictions—and they operate independently of each other.

The first layer is company policy. Every public company that takes Section 16 compliance seriously—and that is now the vast majority—maintains a written insider trading policy that defines when insiders can and cannot trade. These policies establish recurring quarterly blackout periods tied to earnings, plus the ability to declare ad hoc event-driven blackouts on short notice. They also require insiders to seek pre-clearance from a compliance officer before any trade. According to Perkins Coie’s Public Company Handbook, these policies are the primary tool companies use to prevent insider trading violations before they happen.

The second layer is federal law. Regulation BTR, which implements Section 306(a) of the Sarbanes-Oxley Act of 2002, imposes a separate trading prohibition that kicks in automatically when a company’s pension plan goes into lockdown. This rule applies regardless of whether the company has any written policy at all. The two layers can overlap, run simultaneously, or each trigger independently.

Layer One: The Quarterly Earnings Blackout

The most common restriction is the quarterly earnings blackout. When a quarter nears its end, insiders start accumulating knowledge about how the business performed—revenue trends, margin pressures, deal closures. That knowledge becomes material nonpublic information before the earnings report is filed. So companies close the trading window weeks before the quarter ends and reopen it only after results are public.

According to Perkins Coie’s Public Company Handbook, typical blackout periods begin two to four weeks before the end of the fiscal quarter and end after the first or second full business day following the company’s earnings release. Wharton research published via the Harvard Law School Forum on Corporate Governance found that this structure typically produces a trading window of approximately six weeks per quarter—beginning two to three trading days after the prior quarter’s earnings release and closing two to three weeks before the current quarter ends.

A White & Case survey of 50 public company policies published on the Harvard Law School Forum found that 72% of companies surveyed impose a specified quarterly blackout period. Thirty percent begin their blackout approximately two weeks before quarter-end; 44% reopen the window one full trading day after earnings are released, and 28% wait two trading days.

In practice, insiders may have fewer than six weeks in any given quarter where they can actually trade—and that window shrinks further once you add pre-clearance lead times.

Layer Two: Regulation BTR and the Pension-Fund Lockout

The second layer comes from federal law rather than company policy. Regulation BTRimplements Section 306(a) of the Sarbanes-Oxley Act of 2002. It prohibits directors and executive officers from purchasing, selling, or transferring company equity securities acquired in connection with their employment during any period when the company’s pension plan participants are locked out.

A Regulation BTR blackout is triggered when 50% or more of participants in all of the company’s individual account plans—think 401(k) accounts—cannot trade company equity held in those plans for more than three consecutive business days. This can happen during plan transitions, fund lineup changes, or administrative restructurings. When it does, the company must provide directors and executive officers with advance notice of the blackout period and file that notice on Form 8-K.

Special (Ad Hoc) Blackouts: When the Window Slams Shut Early

Beyond the recurring quarterly cycle, companies routinely impose event-driven blackoutson short notice. An M&A negotiation, an FDA decision, a major executive departure, a material contract win—any of these can cause the compliance officer to close the window for a subset of insiders or for everyone until the event becomes public information. According to Perkins Coie, these event-specific blackout periods are imposed “for applicable insiders while the event (or information) remains material and nonpublic.”

Before the SEC’s 2022 disclosure rule, these ad hoc restrictions were entirely invisible to the public. The only indirect evidence came from the data itself. Wharton researchers identified these ad hoc windows by looking for anomalously low Form 4 activity in the weeks preceding unusual 8-K filings related to asset acquisitions, disposals, or other material events. The silence in the Form 4 data was itself a signal that something was happening behind closed doors.

Pre-Clearance: The Gate Inside the Window

Even when the quarterly window is open and no ad hoc blackout is in force, most companies require insiders to obtain explicit approval before trading. This pre-clearance process typically requires insiders to submit a request to the company’s CFO, general counsel, or designated compliance officer at least two business days before initiating any transaction.

The compliance officer can approve, deny, or impose conditions—for example, restricting the time window during which the approved trade must be executed. If news breaks or circumstances change after approval but before the trade executes, the approval is effectively voided. Perkins Coie notes that companies should mandate pre-clearance separately from any Rule 10b5-1 plan adoption procedures—the two processes are distinct.

Pre-clearance is not reflected on a Form 4. The filing shows the transaction date, not when clearance was requested or granted. But the transaction date is what matters for your signal-quality assessment: if the trade date falls within a known open window, clearance was almost certainly obtained through normal channels.

How the 2022 SEC Rule Brought This into the Open

Until recently, most of the corporate calendar described above was entirely private. Companies drafted their insider trading policies as internal documents and had no obligation to disclose the specifics. That changed with the SEC’s December 2022 final rules (Release No. 33-11138), which received unanimous approval from all five Commissioners—a notably rare occurrence.

The rule added a new requirement: companies must file their insider trading policy as Exhibit 19 to their annual Form 10-K, or explain its absence. Calendar-year filers first complied with this requirement in early 2025, when they filed their 2024 annual reports. As the Harvard Law School Forum on Corporate Governance noted, this created a comprehensive public record of blackout window definitions for the first time in the regulation’s history.

To find a company’s Exhibit 19 on EDGAR: go to EDGAR company search, search the company’s most recent 10-K filing, and look in the exhibit index for “Exhibit 19” or “Insider Trading Policy.” The document will spell out exactly when the quarterly blackout begins (typically a date relative to quarter-end) and when it lifts (typically one or two days after earnings). Smaller reporting companies had until October 2023 to comply with the quarterly disclosure portions of the rule, per KPMG’s analysis of the amendments.

Rule 10b5-1 Plans: The Exception That Trades Through Blackouts

There’s one important carve-out to the blackout framework: pre-approved Rule 10b5-1 trading plans are explicitly exempted from both quarterly blackouts and Regulation BTR restrictions. Once an insider establishes a compliant 10b5-1 plan during an open window without possessing MNPI, the trades scheduled under that plan can execute automatically even if a blackout period is later in force.

This is why you will sometimes see Form 4 Code S (sale) transactions filed during what appears to be a blackout window. If the footnotes say “pursuant to a Rule 10b5-1 trading plan,” the sale was scheduled before the window closed and is not a discretionary decision. As Perkins Coie notes, the insider trading policy should explicitly exclude trades under appropriately established 10b5-1 plans from both pre-clearance requirements and blackout restrictions.

The December 2022 SEC amendments significantly tightened this exemption. Officers and directors must now wait the later of 90 days after plan adoption or two business days after the quarterly financial disclosure (capped at 120 days) before the first trade can execute. Other employees face a 30-day minimum cooling-off period. KPMG’s analysis of the rule explains that overlapping plans are also now prohibited, and single-trade plans are limited to one per 12-month period. For more on how these plans work in practice, see our guide to how Rule 10b5-1 trading plans work.

RSUs Vesting During a Blackout: Why Code “F” Shows Up in Closed Windows

If you’ve spent time reading Form 4 filings, you’ve probably noticed Code F transactions—shares withheld for taxes—appearing during periods that look like they should be blackout windows. This is one of the most common sources of confusion for investors, and the explanation is straightforward.

When restricted stock units (RSUs) vest, the IRS treats the vesting as ordinary income. Companies typically satisfy that tax obligation by withholding a portion of the vesting shares rather than requiring the employee to come up with cash. The company, not the employee, initiates this transaction—it is mechanical, not volitional. Because no discretionary trade is occurring, most companies permit this share-withholding to proceed even during a closed trading window.

According to a National Association of Stock Plan Professionals (NASPP) analysis, the 2022 NASPP/Deloitte Tax Equity Administration Survey found that only 35% of companies prohibit share withholding during blackout periods—meaning 65% of companies allow Code F transactions to proceed in closed windows. So when you see a Form 4 with a Code F transaction dated during what appears to be a blackout, that is almost certainly routine tax withholding, not a red flag.

What This Means for Reading Form 4 Signals on MarketPeel

The blackout calendar is a signal-quality filter, not just a legal compliance framework. Every open-market purchase (Code P) you see on a Form 4 happened at a specific point in the corporate calendar—and that timing matters.

An open-market purchase filed shortly after an earnings release sits squarely inside the open trading window. The insider had the full picture: results were public, the window was open, pre-clearance was in place—and still chose to buy. That is the signal you want to see. The Wharton research found this is exactly when insider buying concentrates—boards actually adjust when the window reopens based on how quickly information is incorporated into prices after the earnings announcement.

A purchase filed in the middle of a fiscal quarter is harder to interpret. You don’t know whether an ad hoc blackout was in force for other insiders—or whether this particular insider was exempt from it. A survey of Exhibit 19 filings found significant variation across companies in both the start of the quarterly blackout and which employees it covers, so mid-quarter trades at one company tell a different story than the same timing at another.

The practical workflow: check the Form 4 transaction date against the company’s Exhibit 19 window definition on EDGAR, then ask whether the trade falls within the open window. If it does, weight the signal accordingly. If the transaction date falls during what should be a blackout, check the footnotes—a 10b5-1 footnote or a Code F explains it away; anything else is worth a second look.

The Form 4 transaction codes give you the what; the blackout calendar gives you the when. Put them together and the signal strength of any given open-market purchase becomes much clearer.