What Is Gun Jumping in M&A?

Updated October 2026 · 5 min read · Anweshna

Exposure 1: acting before the waiting period ends

In the US, the Hart-Scott-Rodino Act provides that no person may acquire voting securities or assets of another person, above the reporting thresholds, unless both file notification and the waiting period has expired.^[1] The waiting period begins when the agencies receive the completed notification. It ends on the thirtieth day after that, or the fifteenth for a cash tender offer, unless it is extended.^[1] Before it expires, the agencies can require additional information and documents, the request usually called a "second request", and that extends the timetable.^[1]

The size thresholds in the statute are adjusted and republished every fiscal year, so the figures printed in the statute itself are not current.^[1][2] Check the current figures before deciding a deal is reportable.

The exposure is about beneficial ownership and control in practice, not just the formal closing. Conduct that commonly raises the issue includes:

• the buyer approving or vetoing the target's ordinary-course decisions, such as pricing, customer contracts and hiring;
• buyer staff directing the target's employees or sitting in its operating meetings with authority;
• combining sales efforts, or telling customers the companies are already one;
• moving money, assets or people before closing.

The penalties are civil, and per day. The statute prints a maximum of $10,000 for each day of violation,^[1] but federal civil penalties are adjusted for inflation. The FTC announced in September 2026 that its 2025 penalty levels would continue to apply during 2026.^[3] Use the current adjusted figure, not the printed one.

Exposure 2: coordinating with a competitor before closing

The second exposure exists whether or not a filing is needed. Section 1 of the Sherman Act declares illegal every contract, combination or conspiracy in restraint of trade.^[4] Until closing, the buyer and target are separate companies, and if they compete, exchanging competitively sensitive information or agreeing on conduct can be treated as coordination between competitors rather than deal preparation. Unlike the waiting period, this exposure doesn't disappear if the deal is abandoned: the information has already been shared.

Where diligence and integration planning fit

Buyers are allowed to investigate and to plan. The line falls between planning and doing, and between reviewing and controlling.

• Generally fine with care: reviewing documents, building integration plans that take effect after closing, standard covenants that protect the target's value until closing (no unusual asset sales, no new debt outside the ordinary course).
• Needs a clean room: reviewing competitively sensitive data such as customer-level pricing, margins, bid strategy and wage detail. See our guide to M&A clean rooms.
• Needs counsel before anyone does it: anything that gives the buyer a say over the target's day-to-day business, or that changes how either company competes before closing.

The most common mistakes

1. Treating a clean room as the whole answer. It controls who reads what. It does nothing about who runs the business.
2. Over-broad covenants. Purchase agreement covenants that require buyer consent for ordinary decisions can hand the buyer control early.
3. Integration teams that start early. Planning is fine; giving instructions to target staff isn't.
4. Customer messaging. Telling customers "we're one company now" before closing.
5. Forgetting non-US regimes. Other jurisdictions have their own suspensory rules and timetables. A US-only checklist doesn't cover a cross-border deal.

Where screening fits, and doesn't

Screening documents is reviewing, not controlling, so it sits on the safe side of the first exposure. For the second, what matters is who sees the results. Competitively sensitive documents should be screened inside a clean room, with results released to the deal team only after review. Anweshna's Clean Rooms add-on is built around that release step. Regulatory and merger-control issues are also one of the 15 M&A categories it screens for, and one of the seven that can block a deal.

A pre-closing checklist

• Is the deal reportable, and when does the waiting period end?
• Do the parties compete anywhere, including in buying from the same suppliers or hiring the same people?
• Is there a clean room and a named clean team for competitively sensitive material?
• Do the interim covenants protect value without giving the buyer a say over ordinary-course decisions?
• Has everyone on the integration team been told what they may and may not do before closing?
• Are customer and employee communications reviewed by counsel before they go out?
• Which non-US merger-control regimes apply, and what are their timetables?

Bottom line

Gun jumping is two problems: acting like the owner before clearance, and acting like a co-conspirator before closing. Track the waiting period, keep covenants to what protects value, screen sensitive material inside a clean room, and keep integration on paper until closing day. For approval timelines in banking deals, see bank merger regulatory approval.

Screen deal documents without moving control →