What is HSR?

Before many US deals can close, the companies must tell the antitrust agencies and wait.

The rule comes from the Hart-Scott-Rodino Act, so the review is called HSR. The agencies are the FTC and the Justice Department.

The wait gives them time to check whether the deal would harm competition, before the companies combine.

Say Woodgrove agrees to buy Litware for $2 billion. Both file with the agencies, and the deal can't close until the wait ends.

Whether a deal needs a filing depends mostly on its size. The threshold is updated every year.

Since February 17, 2026, it's $133.9 million. Below that, a deal usually doesn't need a filing. A bigger one often does, depending on the companies' size and some exemptions.

The filing also has a fee. Since the same date, it runs from $35,000 to $2.46 million, rising with the deal's size.

The wait usually starts once both companies have filed, and lasts 30 days. In a cash tender offer, it's 15 days from the buyer's filing.

The agencies can also end it early when the companies ask. This is called early termination.

If neither agency acts, the wait runs out. The deal is then cleared under HSR, and can close once its other closing conditions are met. The agencies can still challenge it later.

Before the wait ends, an agency can send a second request: a demand for many more documents and data.

The deal then usually can't close until both companies have substantially complied, and 30 more days have passed. In a cash tender offer, it's 10 days after the buyer complies.

Complying often takes months. For the 16 significant US merger investigations concluded in 2025, the average from announcement to conclusion was 12.3 months.

Few deals get a second request. In the year to September 30, 2025, 41 of the 1,944 deals that could get one did: 2.1%. For deals over $10 billion, it was 21.1%.

These are the usual ways an HSR review ends. Some cases pass through more than one:

Cleared

The wait runs out, or an agency ends it early. The deal can close once its other conditions are met.

Settled

The companies agree to changes, such as selling part of a business, and the agency lets the deal go ahead.

Challenged in court

The agency asks a federal court to block the deal. The case can end in a ruling, a settlement or the deal being given up.

Given up

The companies abandon the deal, often once they learn the agency is likely to challenge it.

A deal that needs HSR can't close before the wait ends. A second request usually pushes the expected close back by months.

If the deal closes later, the same dollar gain is spread over more time. So the annualized spread falls, even if the price doesn't move.

If a court blocks the deal, the companies often end the agreement, and the deal breaks. The review itself asks nothing of holders.

HSR's stages on the deal page:

Not filed

The parties haven't filed yet.

Filed

Filed, and the waiting period is running.

Second request

The agencies asked for more information.

Challenged

The FTC or the Justice Department sued to block the deal, or said it will.

Cleared

The waiting period expired or was ended early.

Failed

A court blocked the deal, or the parties gave it up because of the review.

Not required

The filings say no HSR filing is needed.

On the list, the Regulatory column shows HSR when it leads the row, such as HSR wait ends Oct 16. While HSR is pending, it's also under Still needed. The HSR filter picks deals by where their HSR stands.

Point at the Regulatory column, or focus it, for the regulatory card. It gives HSR's stage in words, such as Waiting period, ends Oct 16, and the date's type. It adds a line on what the stage is when its name doesn't say, and the filing it comes from, which opens its quote.

Sometimes the wait's end passes before any filing says what happened. Then the column reads HSR wait ended Oct 2, no result, and the card Waiting period ended Oct 2, no result filed.

The dots stop short of cleared until a filing says so. When the filings give no stage, the dots are dashed.

The regulatory card draws each approval as three dots, filed, under review, cleared, beside its stage in words: