Antitrust Law

Antitrust law is the set of federal statutes — the Sherman Act (1890), the Clayton Act (1914), and the FTC Act (1914) — that prohibit anticompetitive business conduct and merger-driven concentration. The core idea: markets serve consumers better when companies compete rather than collude, dominate, or merge until competition disappears. The DOJ Antitrust Division and the FTC share enforcement, both reviewing major mergers and suing companies that fix prices, allocate markets, or maintain monopoly power through exclusionary conduct. For most households, antitrust law is invisible until it isn't — it's the reason airline prices dropped after deregulation, the reason generic drugs enter markets when brand monopolies are challenged, and the reason your cable or internet bill may be what it is partly because regulators approved (or failed to block) past consolidation in those industries.

Current Law (2026)

Parameter	Value
Governing laws	Sherman Act (1890), Clayton Act (1914), FTC Act (1914)
Enforcing agencies	DOJ Antitrust Division + FTC (dual enforcement)
Sherman Act — restraint of trade	Felony; up to $100M corporate / $1M individual fine + 10 years prison
Sherman Act — monopolization	Felony; same penalties as restraint of trade
Clayton Act — mergers	Pre-merger notification required above HSR threshold (~$133.9M for 2026)
Private actions	Treble damages (3x actual harm) + attorney's fees
State enforcement	State attorneys general can sue on behalf of residents

Legal Authority

15 U.S.C. § 1 — Restraint of trade (every contract, combination, or conspiracy in restraint of trade is illegal; felony penalties)
15 U.S.C. § 2 — Monopolization (monopolizing, attempting to monopolize, or conspiring to monopolize is a felony)
15 U.S.C. § 7 — "Person" or "persons" defined (includes corporations and associations for Sherman Act purposes)
15 U.S.C. § 12 — Clayton Act definitions (defines "person," "commerce," "antitrust laws," and "labor dispute" for Clayton Act purposes)
15 U.S.C. § 13 — Price discrimination (Robinson-Patman Act: unlawful for any person engaged in commerce to discriminate in price between different purchasers of commodities of like grade and quality where the effect may substantially lessen competition)
15 U.S.C. § 14 — Tying arrangements and exclusive dealing (unlawful to lease, sell, or contract on condition that the purchaser shall not deal in competitor's goods, where the effect may substantially lessen competition)
15 U.S.C. § 15 — Treble damages (any person injured in business or property by reason of antitrust violation may sue and recover threefold the damages sustained, plus attorney's fees)
15 U.S.C. § 17 — Labor exemption (labor organizations are not combinations in restraint of trade; antitrust laws do not apply to legitimate union activity)
15 U.S.C. § 18 — Acquisitions and mergers (no person shall acquire stock or assets of another person where the effect may be substantially to lessen competition or tend to create a monopoly; Hart-Scott-Rodino premerger notification requirements)
15 U.S.C. § 26 — Injunctive relief (any person, firm, or corporation threatened with loss or damage by antitrust violation may sue for injunctive relief in federal court)
15 U.S.C. § 1291 — Sports broadcasting exemption (joint TV deals by professional sports leagues are exempt)

Implementing Regulations (16 CFR)

16 CFR Part 801–803 — Hart-Scott-Rodino (HSR) premerger notification: filing requirements for mergers/acquisitions above the notification threshold (~$133.9M in 2026; effective Feb. 17, 2026, up from $126.4M in 2025); notification form content; 30-day waiting period; second request procedures; exemptions for certain transactions
16 CFR Part 802 — HSR exemptions: transactions exempt from notification (acquisitions of voting securities solely for investment, certain foreign transactions, acquisitions by regulated entities, intra-person transactions)
16 CFR Part 803 — HSR transmittal rules: filing procedures, calculating the "size of transaction" and "size of person" tests, notification obligations for joint ventures
DOJ/FTC Merger Guidelines (2023 revision) — Framework for evaluating competitive effects of mergers: market definition, concentration analysis (HHI), competitive effects, entry/expansion, efficiencies, failing firm defense — while not codified in CFR, these guidelines are the de facto regulatory standard applied to all merger reviews
16 CFR Part 3 — Rules of Practice for Adjudicative Proceedings (42 sections — the complete FTC administrative enforcement rulebook governing how the Commission prosecutes antitrust and consumer protection actions through its in-house tribunal). Key provisions:
- § 3.11 — Complaint: the Commission files a complaint against a respondent alleging violation of the FTC Act, Sherman Act, or Clayton Act; the complaint must be served within 5 days of issuance; the respondent must answer within 20 days (§ 3.12)
- § 3.21 — Prehearing conferences: the Administrative Law Judge (ALJ) convenes a scheduling conference early in the proceeding; the schedule typically calls for the hearing to begin within 5–6 months of the complaint — a pace much faster than federal court and a significant advantage for FTC in merger cases where speed matters
- § 3.31 — Discovery: parties may take depositions, serve interrogatories, and request documents; FTC administrative discovery rules are generally narrower than federal court discovery, limiting depositions to persons under the respondent's control plus third-party witnesses; documentary discovery from non-parties follows a separate CID (Civil Investigative Demand) process
- § 3.41 — Evidence: FTC administrative proceedings follow relaxed evidentiary rules compared to federal court — hearsay is generally admissible; the ALJ weighs reliability; expert testimony may be presented by written submission rather than live direct examination
- § 3.51 — Initial decision: the ALJ issues a written initial decision (findings of fact, conclusions of law, and proposed order) typically within 4 months of the close of the hearing record
- § 3.52 — Appeal to Commission: either party may appeal the initial decision to the full Commission; the Commission may also review on its own motion; Commission review is de novo on issues of law and deferential on ALJ factual findings
- § 3.72 — Consent orders: most FTC administrative proceedings end in consent orders rather than a fully litigated decision; consent orders are published for 30 days of public comment before becoming final; they bind the respondent for 20 years and may be enforced by federal district court with civil penalties up to $51,744 per violation per day for knowing violations
The FTC administrative track and federal district court enforcement are parallel tools. For mergers, the FTC more frequently files in federal district court for a preliminary injunction to block the deal — if the court grants it, the deal usually dies without a full administrative trial. For conduct cases (unfair methods of competition, deceptive practices), the administrative route produces a cease-and-desist order without the ability to get monetary relief unless the conduct caused consumer harm subject to a separate disgorgement action. The Supreme Court's AMG Capital Management v. FTC (2021) decision eliminated the FTC's ability to seek monetary relief directly under § 13(b) of the FTC Act, significantly limiting the value of the administrative enforcement route for cases where restitution to consumers was the primary goal.
16 CFR Part 240 — Guides for Advertising Allowances and Other Merchandising Payments and Services (15 sections — the FTC's interpretive guides implementing sections 2(d) and 2(e) of the Robinson-Patman Act, which prohibit sellers from discriminating among competing customers in the payment of advertising allowances or the furnishing of promotional services; the Robinson-Patman Act is a 1936 antitrust statute designed to protect smaller retailers from the purchasing advantages of large chain stores; authority: 15 U.S.C. § 13; 15 U.S.C. § 45):
- § 240.1 — Purpose: the guides help businesses comply with Robinson-Patman §§ 2(d) and 2(e), which make it unlawful for a seller to pay advertising allowances to some competing customers but not others unless the payments are made available on proportionally equal terms to all competing customers who buy for resale; the guides are not regulations but are given significant weight in FTC enforcement proceedings and private litigation
- § 240.2 — Applicability: the Robinson-Patman price discrimination provisions apply to a seller (manufacturer, wholesaler, distributor) who sells products for resale in interstate commerce; section 2(d) covers payments for advertising or other promotional services performed by the customer; section 2(e) covers the seller's direct provision of services and facilities to customers; both sections require that benefits be made available on proportionally equal terms
- § 240.5 — Competing customers: "competing customers" are all businesses that compete with each other in the resale of the seller's products at the same functional level of distribution — for example, all retailers who buy the same brand of product from the same seller; competing customers must be offered the same advertising allowances or promotional services; the seller cannot pay allowances to chain stores but not to independent retailers who compete against those chains in the same market
- § 240.7 — Proportionally equal terms: a seller who offers advertising allowances must do so on proportionally equal terms — the amount of the allowance must be proportional to the customer's purchases from the seller; a customer who buys twice as much may receive twice the advertising allowance; payments calibrated to purchases automatically satisfy the proportionality requirement; the seller cannot pay a flat fee to large customers without offering the same proportional benefit to smaller ones
- § 240.9 — Need to affirmatively notify customers: a seller must affirmatively inform all competing customers of the availability of advertising allowances — it is not enough to tell some customers and let others find out on their own; notification must include the specifics (how much is available, how to claim it, what promotional activities qualify); failure to notify some customers while paying others violates the Act even if the seller would have paid any qualifying customer who asked
- § 240.10 — Functional availability: the promotional offers made to competing customers must be useable in a practical sense by those customers — a seller cannot satisfy the proportionality requirement by offering a multi-million-dollar national advertising campaign to small retailers who cannot use it; the seller must offer alternative promotional plans that smaller customers can actually employ (local advertising, in-store promotions, coupons); if no practical alternative is available, the allowance may need to be provided in cash
- § 240.12 — Checking customer use: a seller who pays advertising allowances must take reasonable precautions to verify that the customer actually performs the promised promotional activity; payment for promotional services that are not performed is not a bona fide advertising allowance but a covert price concession — and unverified payments cannot be used to justify equivalent payments to other customers
- § 240.14 — Meeting competition defense: a seller may discriminate in advertising allowances if it can show the payments were made in good faith to meet a competitor's equally discriminatory allowances; the meeting-competition defense preserves flexibility but requires that the seller have a reasonable basis for believing the competitor was offering the same arrangement
The Robinson-Patman Act's advertising allowance provisions are among the most complex and overlooked aspects of antitrust compliance for consumer goods manufacturers and wholesalers. Large retailers routinely negotiate advertising allowances, slotting fees, cooperative advertising arrangements, and promotional services packages — all of which must be offered on proportionally equal terms to competing buyers. The FTC has historically been more active in Robinson-Patman enforcement than DOJ; private Robinson-Patman litigation (which allows treble damages) is significant, particularly in the grocery, drug, and hardware wholesale distribution sectors. The guides in Part 240 are the primary practical compliance resource for businesses navigating these requirements.

How It Works

Antitrust law is the body of federal law that promotes competition and prevents monopolistic business practices. Three foundational statutes — the Sherman Act, Clayton Act, and FTC Act — work together to prohibit anticompetitive agreements, prevent monopolization, block harmful mergers, and stop unfair competition.

The Sherman Act (1890) is the cornerstone: Section 1 (15 U.S.C. § 1) outlaws "every contract, combination, or conspiracy in restraint of trade," with courts distinguishing between per se illegal agreements — price-fixing, bid-rigging, and market allocation among competitors, always illegal regardless of business justification — and those evaluated under the "rule of reason," which weighs anticompetitive harms against procompetitive benefits. Section 2 targets monopolization: it is not illegal to be a monopoly, but it is illegal to acquire or maintain monopoly power through anticompetitive conduct such as predatory pricing, exclusive dealing, or tying arrangements. The Clayton Act (1914) (15 U.S.C. § 18) fills specific gaps: Section 7 prohibits mergers whose effect "may be substantially to lessen competition" — a lower standard allowing enforcement before a monopoly fully forms — and the Hart-Scott-Rodino Act requires pre-merger notification to the FTC and DOJ for deals above approximately $133.9 million (2026 threshold; effective Feb. 17, 2026), triggering a 30-day review window. (For related intellectual property monopoly protections, see Copyright Law and Patent Law.)

Both the DOJ Antitrust Division and the FTC enforce federal antitrust law with different tools: DOJ can bring criminal prosecutions — price-fixing is a federal felony with corporate fines up to $100 million and individual sentences up to 10 years — and civil suits; the FTC brings administrative and civil proceedings only. The agencies divide merger review by industry — DOJ typically handles telecommunications, banking, and defense; FTC handles healthcare, technology, retail, and energy. Private plaintiffs who prove antitrust injury in federal court may recover treble damages plus attorney's fees (15 U.S.C. § 15), turning every victim of anticompetitive conduct into a potential enforcer and making price-fixing class actions economically viable. Certain activities are exempt by statute — labor union organizing, agricultural cooperatives, insurance (McCarran-Ferguson Act, partially), joint sports broadcasting deals, and certain export activities — and the "state action" doctrine exempts conduct that states actively supervise and clearly authorize.

How It Affects You

If you're a consumer who suspects you've overpaid because of price-fixing, you have a direct legal remedy — and you may already be part of a pending class action. The Clayton Act's treble damages provision means that if a company illegally fixed prices or colluded with competitors, victims can recover three times their actual overcharge, plus attorney's fees. In practice, most consumer antitrust recoveries come through class actions — the NAR real estate commission antitrust settlement ($418 million, 2024) is the most recent major example, restructuring how buyer's-agent compensation works nationwide. Before that, significant settlements covered LCD panels, optical disk drives, generic drug "pay-for-delay" deals, and air cargo surcharges. To find pending antitrust class actions that might cover products or services you bought, check resources like classaction.org and topclassactions.com — courts post class certification notices publicly. One important caveat under federal law: only direct purchasers typically have standing to sue under the Sherman Act (Illinois Brick doctrine) — but about half the states allow indirect purchasers (consumers) to sue under state antitrust laws, so state AG actions often accompany federal cases.

If you run a business, the clearest antitrust risk is conversation with competitors about pricing, market allocation, or customers. Under the per se rule, agreements between competitors to fix prices, divide markets, or allocate customers are illegal — no business justification matters, and intent to harm competition doesn't need to be proven. Criminal prosecution is real: price-fixing is a federal felony with corporate fines up to $100 million and individual sentences up to 10 years. Even informal agreements — a phone call, an email, a discussion at an industry conference — can constitute a conspiracy. No-poach agreements (promising not to hire each other's employees) between competing employers are now treated as potentially per se illegal by DOJ. If you're considering a merger or acquisition with a total transaction value above $133.9 million (the 2026 HSR threshold, effective Feb. 17, 2026), budget for mandatory pre-merger filing — currently requiring detailed competitive analysis that takes weeks to prepare — and a 30-day waiting period (potentially months if the agencies issue a Second Request). Small deals are rarely scrutinized; deals in highly concentrated industries (healthcare, tech, defense) face intensive review.

If you're a tech platform user or depend on tech infrastructure, the antitrust cases pending against major tech companies could reshape the products you use. Judge Mehta's August 2024 ruling that Google illegally maintained its search monopoly through exclusive default agreements with Apple is the most significant antitrust ruling since United States v. Microsoft (2001). The remedy phase — ongoing in 2026 — could include forced sale of the Chrome browser, prohibition on default search agreements (potentially disrupting Apple's $15–$20 billion annual payment from Google), and mandatory sharing of search data with competitors. A separate DOJ case against Google's advertising technology monopoly is proceeding toward remedy. The FTC's case against Meta (alleging the Instagram and WhatsApp acquisitions illegally maintained Facebook's social media monopoly) is also pending. These cases matter to users because structural remedies — divestitures, behavioral conditions, data access requirements — directly affect the competitive landscape of the products millions of people use daily.

If you're part of a merger or acquisition team for a deal above the HSR threshold, the 2024 HSR rule overhaul substantially increased compliance complexity. The new rules require much more detailed information in initial filings — including deal rationale, draft agreements, competitive overlaps, and supply relationship disclosures — making HSR preparation more like early-stage merger review than the previous administrative filing. Budget 4-8 weeks for preparing an HSR filing for a complex deal. The 30-day initial waiting period starts when both parties file; agencies can issue a Second Request for additional documents before the waiting period expires — a Second Request typically takes 6-12 months to respond to and costs millions in legal and consulting fees. The 2023 Merger Guidelines' lower effective scrutiny thresholds (HHI 1,800 with a 100-point increase from the deal) mean more mergers face enhanced review than under prior guidelines, even with somewhat moderated FTC enforcement posture under Chair Ferguson.

State Variations

Most states have their own antitrust statutes modeled on federal law. Key differences:

State AG enforcement: State attorneys general can sue under both state and federal antitrust law, and frequently bring cases alongside or independently of federal agencies
State merger review: Some states review mergers independently, particularly in healthcare and energy
Indirect purchaser standing: Many states allow indirect purchasers (consumers) to sue for antitrust damages; federal law generally limits standing to direct purchasers (Illinois Brick)
State-specific exemptions: States may exempt certain industries from state antitrust law

Pending Legislation (119th Congress)

HR4107 — Antitrust Accountability and Transparency Act — Tightens review of antitrust consent judgments, expands remedies and disclosures, speeds timelines, and lets states and the FTC intervene
HR3548 / HR6830 — Fair Competition for Small Business Act — Lets state attorneys general sue for damages from price discrimination under the Clayton Act (Robinson-Patman violations)
HR3638 — Antitrust Freedom Act — Would exempt private, voluntary economic coordination among individuals from three major federal antitrust laws
HR6546 — Merger Process Review Act — Requires IGs to audit how federal banking regulators handle mergers, tracking timeliness and effects on competition
HR3200 — License Monopoly Prevention Act — Requires Commerce to review export license applications for monopoly risk
S 4185 — Stop Subsidizing Giant Mergers Act. Status: Introduced.
HR 6248 — Healthy Competition for Better Care Act: ban anticompetitive contract clauses that limit network choices and steer patients. Status: Introduced.

Recent Developments

DOJ won landmark Google antitrust cases (2024–2025): In August 2024, U.S. District Judge Mehta ruled that Google illegally maintained its search engine monopoly through exclusive default search agreements with Apple and other device manufacturers — the first major Section 2 monopolization ruling against a Big Tech company in decades. The remedies phase began in 2025, with DOJ seeking structural remedies including potential divestiture of Chrome, forced licensing of search data, and prohibition on exclusive default agreements. Separately, Google's advertising technology monopolization case proceeded toward verdict in 2025. These cases are the most significant application of the Sherman Act to the digital economy since the Microsoft case (2001).
2023 Merger Guidelines tightened scrutiny; Trump FTC under new leadership (2025): The Biden DOJ/FTC 2023 Merger Guidelines lowered effective HHI thresholds for enhanced scrutiny (1,800 HHI market concentration; 100 point increase in HHI from a deal) and added new presumptions of anticompetitive harm. The Trump administration replaced FTC Chair Lina Khan with Andrew Ferguson in early 2025. Ferguson signaled continuation of some Khan-era Big Tech enforcement while shifting focus to social media censorship as an antitrust concern — a novel theory without established legal support. Merger enforcement volume moderated somewhat in 2025.
HSR premerger notification thresholds increased (February 2026): The FTC raised HSR filing thresholds for 2026: the minimum "size of transaction" threshold increased to $133.9 million (from $126.4 million in 2025), effective Feb. 17, 2026. Maximum filing fees rose to $2.46 million for the largest deals. Deals above the size-of-transaction threshold involving parties that meet size-of-person tests must be reported to DOJ and FTC before closing and wait through a review period. The HSR rules were also substantially reformed in 2024 to require significantly more detailed information in initial filings, increasing the compliance burden for deal parties and their counsel.
Real estate commission antitrust settlement reshaped the industry (2024): The National Association of Realtors settled a massive antitrust class action in March 2024 for $418 million, agreeing to eliminate rules requiring seller's agents to offer buyer's-agent compensation through MLS listings. The settlement, which took effect August 2024, decoupled buyer and seller agent compensation — buyers must now negotiate their agent's fee separately rather than having it implicitly included in the home price. Economists are studying the effect on agent compensation levels and housing transaction costs; early data showed significant variation in buyer-agent fee structures across markets.