Tender offer rules are the SEC framework that governs any public bid to buy shares of a listed company at a fixed price and deadline. Built on the Williams Act and carried out through Regulations 14D and 14E, they require the bidder to disclose who it is, where the money is coming from, and what it plans to do with the company; keep the offer open for at least 20 business days; pay every tendering shareholder the same top price; and let you withdraw your shares at any point before the deadline. The target company’s board also has to tell you, in writing, whether it thinks you should accept.
When the Rules Apply
The statute never actually defines “tender offer.” Courts identify one by looking at whether a buyer is publicly soliciting a broad group of shareholders, at a premium, on firm terms, within a limited window, with pressure to act.1U.S. Securities and Exchange Commission. Correspondence – Sonic Automotive, Inc. Once a transaction fits that pattern, the full regulatory regime engages.
There is one important gap. Section 14(d)’s disclosure and procedural rules only apply when the bidder’s ownership would cross 5% of a class of equity securities.2Office of the Law Revision Counsel. 15 USC 78n – Proxies Bids for less than 5%, known as mini-tender offers, escape the filing requirements, the 20-day minimum, and the equal-treatment rule.3Securities and Exchange Commission. Commission Guidance on Mini-Tender Offers and Limited Partnership Tender Offers The anti-fraud rules still apply, but the bidder does not have to hand you a disclosure document, and mini-tenders are sometimes priced below the current market. If you get one, check the market price before you do anything else.
What the Bidder Must Tell You
Any bidder crossing the 5% threshold has to file Schedule TO with the SEC, deliver it to the target company, and send it to any exchange trading the stock, all on the day the offer commences. The filing has to identify the bidder and anyone acting as a group with it, state the source and total amount of the purchase funds, explain the purpose of the offer, and lay out any concrete plans for the target after the deal closes. That includes intended changes to management, corporate structure, business operations, or plans for a follow-on merger or going-private transaction.4eCFR. 17 CFR 240.14d-100 – Schedule TO
The financing disclosure matters as much as the price. It’s what lets you judge whether the bidder can actually close.
What the Target Company Must Tell You
The company being bought has 10 business days from the commencement of the offer to publish a statement telling shareholders whether the board recommends accepting, rejecting, taking no position, or is unable to take a position, along with the reasons.5eCFR. 17 CFR 240.14e-2 – Position of Subject Company With Respect to a Tender Offer
If the board goes beyond that and actively campaigns for or against the offer, it also has to file Schedule 14D-9 with the SEC as soon as practicable on the date the solicitation begins. That filing has to disclose director and officer conflicts of interest, any arrangements between target management and the bidder, change-in-control compensation like severance packages, and whether the company is in talks over any competing transaction. Material changes require a prompt amendment.6eCFR. 17 CFR 240.14d-101 – Schedule 14D-9
Equal Treatment: All Holders, Best Price
Rule 14d-10 sets two absolute requirements. The offer has to be open to every holder of the class of securities being sought, and the price paid to any one shareholder has to equal the highest price paid to any other in the same offer.7eCFR. 17 CFR 240.14d-10 – Equal Treatment of Security Holders
The practical effect: a bidder cannot quietly cut a better deal with a large institutional holder to lock up control. If the bidder raises the offer price during the tender period, everyone who already tendered at the lower price automatically gets the higher amount.
The 20-Day Clock, Extensions, and Your Right to Withdraw
Every tender offer has to stay open for at least 20 business days from the date it is first published or sent to shareholders.8eCFR. 17 CFR 240.14e-1 – Unlawful Tender Offer Practices That window is your reading time: Schedule TO, the board’s recommendation, and any competing bids that surface.
If the bidder changes the offer price or the number of shares sought, the offer has to stay open at least 10 additional business days from the date the change is announced.8eCFR. 17 CFR 240.14e-1 – Unlawful Tender Offer Practices
Throughout the offer period, you can withdraw shares you’ve already tendered. That right is central to how the system works. Because tendering early costs nothing, you can put your shares in as soon as you decide the price is acceptable, then pull them back if a higher bid appears or the board comes out against the deal.
Subsequent Offering Periods
After the initial 20-business-day period ends, the bidder may open a subsequent offering period of at least three additional business days. This option is only available when the bidder is offering to buy all outstanding shares of the class, has immediately accepted and paid for shares tendered during the initial period, and offers the same price in both periods.9eCFR. 17 CFR 240.14d-11 – Subsequent Offering Period
The catch: withdrawal rights do not apply during a subsequent offering period. Once you tender in that window, the shares are gone. The subsequent period exists to let stragglers participate on the same terms, but the loss of the withdrawal right means you should be certain before submitting.
Pro Rata Acceptance in a Partial Offer
If the bidder is only buying a set number of shares and more get tendered than that, the bidder has to accept shares pro rata from every tendering shareholder, in proportion to what each person offered.10eCFR. 17 CFR 240.14d-8 – Exemption From Statutory Pro Rata Requirements Tender 1,000 shares into an offer that ends up 50% oversubscribed, and roughly two-thirds of your shares get bought while the rest come back. The rule kills any first-come, first-served scramble.
Anti-Fraud Rules and Insider Trading
Regulation 14E applies to every tender offer, no matter the size, and its broadest provision prohibits fraudulent, deceptive, or manipulative conduct in connection with an offer.
Rule 14e-3 targets insider trading around tender offers specifically. Once the bidder has taken substantial steps toward launching, anyone who has material nonpublic information about the offer and knows or should know it came from the bidder, the target, or their insiders is barred from trading in the target’s securities.11eCFR. 17 CFR 240.14e-3 – Transactions in Securities on the Basis of Material, Nonpublic Information in the Context of Tender Offers The rule is broader than ordinary insider trading law because prosecutors do not have to prove a breach of fiduciary duty. Possession plus knowledge that the information is nonpublic is enough.12SEC Historical Society. Fair To All People – The SEC and the Regulation of Insider Trading Tipping is also prohibited.
Rule 14e-4 stops short tendering. In a partial offer, anyone who tenders has to hold a net long position at least equal to the shares tendered, both at the time of tender and at the end of the proration period.13eCFR. 17 CFR 240.14e-4 – Prohibited Transactions in Connection With Partial Tender Offers Tendering shares you don’t own inflates the apparent tender count and distorts the proration math for shareholders who actually hold the stock.
After the offer closes, the bidder has to either pay or return the tendered shares promptly. The SEC expects settlement within a few business days of expiration, in line with normal industry practice.
Company Buybacks Through a Tender Offer
When a company tenders for its own shares, Rule 13e-4 applies. The core protections mirror third-party offers: at least 20 business days open, withdrawal rights, open to all holders, same price for everyone. The issuer also has to file a Schedule TO disclosing the purpose of the buyback, the source of funds, and the transaction’s effect on the company’s finances. One extra restriction: the company and its affiliates cannot buy shares of the same class outside the tender offer for at least 10 business days after it ends.14eCFR. 17 CFR 240.13e-4 – Tender Offers by Issuers
Enforcement
The SEC can bring cease-and-desist proceedings against ongoing or imminent violations, ordering someone to stop and take compliance steps after notice and a hearing, and can seek a temporary order first if a violation threatens serious investor harm.15Office of the Law Revision Counsel. 15 USC 78u-3 – Cease-and-Desist Proceedings
Civil penalties for Exchange Act violations can reach $236,451 per violation for an individual involved in fraud that causes substantial losses, and more than $1.18 million per violation for entities. For insider trading tied to a tender offer, penalties for a controlling person can exceed $2.6 million.16Securities and Exchange Commission. Adjustments to Civil Monetary Penalty Amounts The SEC also routinely seeks disgorgement of illegal profits, and courts can impose injunctions that bar people from serving as officers or directors of public companies.
Taxes If You Tender
Cash for your shares is a taxable event. Hold the shares more than a year and the gain is a long-term capital gain. For 2026, the rates are 0% on taxable income up to $49,450 for single filers ($98,900 for married filing jointly), 15% above those thresholds, and 20% once taxable income tops $545,500 for single filers ($613,700 joint).17Tax Foundation. 2026 Tax Brackets and Federal Income Tax Rates Shares held a year or less generate short-term gains taxed at your ordinary rate.
The gain is the tender price minus your basis. If you bought at different times and prices, each lot carries its own basis and holding period. In a partial tender, only the shares actually accepted for purchase produce a taxable event. Higher earners should also factor in the 3.8% net investment income tax on top of the capital gains rate.