Regulatory Approvals: HSR, CFIUS and Fairness Opinions

Deals valued above $133.9 million may require a Hart-Scott-Rodino filing and a waiting period before closing, with filing fees from $35,000 to $2.46 million under the thresholds effective February 17, 2026. Investments by foreign persons may fall under CFIUS review, which is mandatory in some cases. When a broker-dealer gives a board a fairness opinion that will be shared with shareholders, FINRA Rule 5150 requires specific conflict disclosures and approval procedures.

Hart-Scott-Rodino premerger notification

The Hart-Scott-Rodino Act requires parties to certain acquisitions to file premerger notification and wait before closing ^[3]. The FTC's filing guide sets out the basic test: a transaction must exceed the size-of-transaction threshold, and for deals in a middle band the parties must also meet a size-of-person test ^[2]. These dollar thresholds are adjusted annually based on changes in gross national product ^[2].

For 2026, the FTC set the size-of-transaction threshold at $133.9 million, effective February 17, 2026 ^[1]. The upper threshold, above which the size-of-person test no longer applies, is $535.5 million, and the size-of-person thresholds are $26.8 million and $267.8 million ^[1][2]. The FTC states that the threshold in effect at the time of closing determines whether a deal is reportable, while the filing fee is determined by the value of the transaction at the time of filing ^[1].

• Less than $189.6 million: $35,000 fee ^[1]
• $189.6 million to less than $586.9 million: $110,000 ^[1]
• $586.9 million to less than $1.174 billion: $275,000 ^[1]
• $1.174 billion to less than $2.347 billion: $440,000 ^[1]
• $2.347 billion to less than $5.869 billion: $875,000 ^[1]
• $5.869 billion or more: $2,460,000 ^[1]

After filing, the parties must wait 30 days, or 15 days for a cash tender offer or bankruptcy ^[3]. The agency may grant early termination, or it may issue a request for additional information, commonly called a second request, which extends the waiting period until the parties comply ^[3].

The HSR form in 2026

According to the FTC, a federal district court vacated the new HSR form that took effect on February 10, 2025, ruling on February 12, 2026, and on March 19, 2026 the court of appeals denied the Commission's motion for a stay pending appeal ^[4]. The FTC is now accepting filings on the form and instructions in place before February 10, 2025, and will also accept the newer form if filers choose to use it ^[4]. On March 25, 2026, the FTC and the Justice Department asked for public comment on the premerger form, with comments due by May 26, 2026 ^[6]. Gibson Dunn reported that on May 26, 2026 the Fifth Circuit held the government's appeal in abeyance until December 31, 2026, and that the agencies anticipate issuing an updated rulemaking by year-end 2026 ^[5]. Any new form would be a proposal until finalized, so filers should check the FTC's current guidance before preparing a filing.

CFIUS review of foreign investment

The Committee on Foreign Investment in the United States is an interagency committee, chaired by the Secretary of the Treasury, that reviews certain transactions involving foreign investment in U.S. businesses for national security risk ^[7]. Parties can file a short declaration, which leads to a 30-day assessment, or a full notice, which starts a 45-day review that may be followed by a 45-day investigation and, if needed, a 15-day presidential decision period ^[7][8]. CFIUS may impose conditions or enter into agreements to mitigate risks, or refer a case to the President ^[7].

Filing is not always voluntary. Declarations are mandatory for certain transactions involving U.S. businesses that produce, design, test, manufacture, fabricate or develop critical technologies, and for certain investments in which a foreign government has a substantial interest ^[8]. In its annual report for calendar year 2025, CFIUS reported 207 notices and 140 declarations, of which 51 declarations were subject to mandatory filing requirements; it conducted investigations of 114 of the 207 notices ^[8]. Treasury is also piloting a Known Investor Program to collect information from foreign investors before they file, and its website states that the program will not change CFIUS's jurisdiction or process ^[9].

Fairness opinions and FINRA Rule 5150

Boards often ask a financial adviser for a fairness opinion, a letter stating whether the consideration in a deal is fair from a financial point of view. When a FINRA member firm issues a fairness opinion to a board knowing or having reason to know that it will be provided to public shareholders, FINRA Rule 5150 requires it to disclose, among other things, whether it has acted as financial adviser to any party and whether its compensation depends on completion of the deal, any material relationships with the parties in the past two years, whether it independently verified the company's information, whether a fairness committee approved the opinion, and whether the opinion addresses the fairness of insiders' compensation relative to public shareholders ^[10]. The rule also requires written procedures for approving fairness opinions, including the use of fairness committees and the process for determining whether valuation analyses are appropriate ^[10].

Key terms

Hart-Scott-Rodino (HSR) Act

The federal law requiring parties to certain acquisitions to notify the FTC and DOJ and observe a waiting period before closing.

Size-of-transaction threshold

The minimum deal value that can trigger an HSR filing, set at $133.9 million effective February 17, 2026.

Size-of-person test

An HSR test based on the parties' sales or assets that applies only to deals in the middle valuation band.

Second request

A request for additional information from the FTC or DOJ that extends the HSR waiting period until the parties comply.

CFIUS

The Treasury-chaired interagency committee that reviews certain foreign investments in U.S. businesses for national security risk.

Declaration (CFIUS)

A short-form CFIUS filing subject to a 30-day assessment, mandatory for certain critical technology and foreign-government transactions.

Fairness opinion

An adviser's opinion to a board on whether deal consideration is fair from a financial point of view.

FINRA Rule 5150

The FINRA rule requiring conflict disclosures and approval procedures for fairness opinions shared with public shareholders.

Check your understanding

Sources

1. [1]Federal Trade Commission, “New HSR thresholds and filing fees for 2026,” January 20, 2026.
2. [2]Federal Trade Commission, “Steps for Determining Whether an HSR Filing is Required,” Accessed November 2026.
3. [3]Federal Trade Commission, “Premerger Notification and the Merger Review Process,” Accessed November 2026.
4. [4]Federal Trade Commission, “HSR Notification Forms, Instructions and Guidance,” Updated March 23, 2026.
5. [5]Gibson, Dunn & Crutcher LLP, “Fifth Circuit Pauses Appeal of Decision Vacating 2024 HSR Rule as Antitrust Agencies Pursue Replacement Rulemaking,” May 26, 2026.
6. [6]Federal Trade Commission, “Federal Trade Commission and Department of Justice Seek Public Comment on the Premerger Notification and Report Form,” March 25, 2026.
7. [7]U.S. Department of the Treasury (CFIUS), “CFIUS Overview,” Accessed November 2026.
8. [8]Committee on Foreign Investment in the United States (U.S. Department of the Treasury), “CFIUS Annual Report to Congress, Report Period: CY 2025,” August 7, 2026.
9. [9]U.S. Department of the Treasury (CFIUS), “Known Investor Program,” Accessed November 2026.
10. [10]FINRA, “5150. Fairness Opinions,” Accessed November 2026.

Educational content only — not legal, tax, or investment advice, or an offer to sell or a solicitation of an offer to buy any security. Rules and data are described as of November 2026 and may change. Securities offered through Umergence LLC, Member FINRA/SIPC.