Guides · Securities

Section 11 Damages and Negative Causation

A Section 11 claim is easier to plead and harder to defend than a Rule 10b-5 claim, and the damages fight works differently. The statute supplies the measure of damages, presumes that any decline in value was caused by the misstatement, and puts the burden on the defendant to prove otherwise. That defense, negative causation, is where most of the expert work happens. This guide covers the formula, the meaning of "value," the defendant's burden, tracing, and the parallel Section 12(a)(2) defense.

Guide 9 of 10 · October 19, 2026 · 11 min read
On this page
  1. Why Section 11
  2. The statutory
  3. Value versus market
  4. Negative causation
  5. Tracing and
  6. Section 12(a)(2)
  7. What each
  8. What to prepare

Why Section 11 differs from 10b-5

Herman & MacLean v. Huddleston set out the contrast. Section 11 "was designed to assure compliance with the disclosure provisions of the Act by imposing a stringent standard of liability on the parties who play a direct role in a registered offering." A purchaser of a registered security "need only show a material misstatement or omission to establish his prima facie case." For the issuer, liability "is virtually absolute, even for innocent misstatements." The Court summarized: "Although limited in scope, § 11 places a relatively minimal burden on a plaintiff." A Section 10(b) plaintiff, by contrast, "must prove that the defendant acted with scienter."

In In re Morgan Stanley Information Fund Securities Litigation, the Second Circuit added that, unlike Exchange Act plaintiffs, "plaintiffs bringing claims under sections 11 and 12(a)(2) need not allege scienter, reliance, or loss causation." Causation moves to the defense, and the burden moves with it.

So the 10b-5 toolkit does not transfer directly. There, the plaintiff's expert builds an inflation ribbon tied to corrective disclosures, as discussed in Loss Causation, Damages and the Inflation Ribbon. Under Section 11, the starting number comes from a statutory formula, and the defense economist must carve out what the misstatement did not cause.

The statutory damages formula

Section 11(e), as quoted by the Second Circuit in McMahan & Co. v. Wherehouse Entertainment, Inc., provides that the suit may "recover such damages as shall represent the difference between the amount paid for the security (not exceeding the price at which the security was offered to the public) and (1) the value thereof as of the time such suit was brought, or (2) the price at which such security shall have been disposed of in the market before suit." The third alternative applies to shares sold after suit but before judgment, measured by the sale price, but only if that produces damages lower than the measure in clause (1).

In practice that gives three measurement points for each share:

  • Held at the time of suit. Amount paid, capped at the offering price, minus value on the date suit was brought.
  • Sold before suit. Amount paid, capped at the offering price, minus the sale price.
  • Sold after suit but before judgment. Amount paid, capped at the offering price, minus the sale price, if that figure is lower than the clause (1) measure.

Two caps apply on top of the formula. Section 11(g), as McMahan quotes it, provides that "[i]n no case shall the amount recoverable under [section 11] exceed the price at which the security was offered to the public." And Section 11(e) limits an underwriter's exposure, as the Supreme Court described it in Slack Technologies, LLC v. Pirani, to the "total price at which the securities underwritten by him and distributed to the public were offered to the public."

The formula is mandatory. In McMahan, the district court had allowed benefit-of-the-bargain damages under Section 11. The Second Circuit reversed, holding that Section 11(e) prescribes the method of calculating damages and "the court must apply that method in every case." The argument that Section 11(e) was only a cap was "belied by the plain language of the statute."

The date of suit therefore matters. Under clause (1), damages are fixed by value when suit is brought, not at the bottom of the decline, so a rebound before filing reduces damages for every share still held.

Value versus market price

McMahan also set out three principles for applying "value" on remand.

First, "the term 'value' in section 11(e) was intended to mean the security's true value after the alleged misrepresentations are made public." Promised value, the court held, was "irrelevant to this calculation."

Second, "the value of a security may not be equivalent to its market price." Congress's use of "value," as distinguished from "amount paid" and "price," indicates that "under certain circumstances, the market price may not adequately reflect the security's value." The court cited decisions adjusting price for unrelated panic selling, but cautioned that instances where market price and value diverge are "unusual and rare" situations, and that "even where market price is not completely reliable, it serves as a good starting point in determining value." On the record before it, the court held that the district court "should begin with the market price to determine the true value of the Debentures."

Third, "as a general rule," a "price decline before disclosure may not be charged to defendants," quoting Akerman, but the defendant "bears the burden of proving that the price decline was not related to the misrepresentations in the registration statement."

For experts, any claim that suit-date value differed from the closing price needs a reasoned valuation, not a bare assertion that the market was wrong.

Negative causation and the defendant's burden

The defense comes from the second half of Section 11(e). As McMahan quoted it: "[I]f the defendant proves that any portion or all of such damages represents other than the depreciation in value of such security resulting from [the] part of the registration statement ... [that contains the material misstatement or omission], such portion of or all such damages shall not be recoverable." The court explained that "any decline in value is presumed to be caused by the misrepresentation in the registration statement," and that this affirmative defense "is known as the defense of 'negative causation.'"

Akerman remains the leading application. Oryx's prospectus overstated earnings for an eight-month period because of a bookkeeping error that posted a subsidiary's sale to March instead of April. The units were offered at $4.75, had fallen to $4.00 by the day before Oryx disclosed the error to the SEC, fell to $3.25 by the day before public disclosure, and then rose to $3.50 by the date of suit. The Second Circuit described the standard: "A defendant's burden in attempting to reduce his liability has been characterized as the burden of 'negative causation.'" That burden is heavy: "Defendants' heavy burden reflects Congress' desire to allocate the risk of uncertainty to the defendants in these cases." But it "is not insurmountable; section 11(e) expressly creates an affirmative defense of disproving causation."

The analysis turned on timing. Measured from public disclosure to the date of suit, "[a]t first blush, damages would appear to be zero because there was no depreciation in Oryx's value between the time of public disclosure and the time of suit." The plaintiffs argued for the earlier SEC disclosure date on an insider-trading theory, but after extensive discovery they "produced absolutely no evidence of insider trading."

The opinion is also a lesson in expert method. The defense study found that Oryx performed at the exact statistical median of one hundred companies that went public around the same time. The plaintiffs compared Oryx with the over-the-counter composite index and with the same new issues over a shorter window. The Second Circuit found both sides' comparisons wanting: "The parties' conflicting comparisons, however, lack credibility because they fail to reflect any of the countless variables that might affect the stock price performance of a single company." It added that "[s]tatistical analyses must control for relevant variables to permit reliable inferences." The court concluded that "the battle of the studies is at best equivocal," and affirmed summary judgment on other grounds: "Defendants met their burden, as set forth in section 11(e), by establishing that the misstatement was barely material and that the public failed to react adversely to its disclosure."

Later decisions apply the same burden. In In re Flag Telecom Holdings, Ltd. Securities Litigation, the Second Circuit contrasted the two statutes: under the Exchange Act the plaintiff proves loss causation, while under the Securities Act "it is the defendant who bears the burden of demonstrating that something other than the misstatement at issue caused plaintiff's loss." The court affirmed a single class of Securities Act and Exchange Act purchasers, but held that in-and-out traders who sold before the corrective disclosure should not have been included because the plaintiffs had not shown they could prove loss causation.

The defense can occasionally win on the pleadings. In In re Britannia Bulk Holdings Inc. Securities Litigation, the Southern District of New York called it "the perhaps unusual one where negative causation is apparent on the face of the Complaint and Defendants have carried their burden of proof." The stock had already fallen from the $15.00 offering price to $1.90 before the only disclosure the complaint relied on, so "the brunt of the collapse had already occurred even before the market was informed." The later drop did not count either, because the disclosure concerned contracts entered into after the IPO and did not correct anything in the offering documents.

Tracing and standing after Slack

Damages are computed only for shares that can be traced to the challenged registration statement. In Slack, the Supreme Court noted that "every court of appeals to consider the issue has reached the same conclusion: To bring a claim under §11, the securities held by the plaintiff must be traceable to the particular registration statement alleged to be false or misleading." It held that "the better reading of the particular provision before us requires a plaintiff to plead and prove that he purchased shares traceable to the allegedly defective registration statement."

Referring to the underwriter cap, the Court observed: "This provision thus ties the maximum available recovery to the value of the registered shares alone." On remand, the Ninth Circuit held that Section 12(a)(2) requires the same showing, and because the plaintiff had previously conceded that he could not trace his shares, it ordered the complaint dismissed with prejudice.

For damages experts, tracing shapes the share count: where registered and unregistered shares trade together, any aggregate figure must exclude shares that cannot be traced.

Section 12(a)(2) and its loss causation defense

Section 12(a)(2) has its own version of the defense in Section 12(b), added in 1995. As the Southern District of New York quoted it in Britannia, the defense applies if the defendant "proves that any portion or all of the amount" otherwise recoverable "represents other than the depreciation in value of the subject security resulting from" the misstatement or omission. In Federal Housing Finance Agency v. Nomura Holding America, Inc., the Second Circuit explained that "[t]he loss causation defense in Section 12 was adapted from the loss causation defense in Section 11(e) of the Securities Act," and that, because Section 12(a)(2) is rescissory, the defense "is a mutual accounting that prevents the buyer from reaping an unjust benefit at the expense of the seller."

The district court opinion after the Nomura bench trial shows how the defense fails. The defendants blamed losses on mortgage-backed certificates on the housing collapse rather than misstatements about loan underwriting. The court held that "[t]he affirmative defense of loss causation requires a defendant to prove that the loss in the value of the security was proximately caused by events unrelated to the phenomena underlying the alleged misrepresentations." It found that poor origination practices were among the factors behind the collapse, and held: "An event cannot be 'intervening' if defendants' misrepresentations, and the underlying facts they concealed, were part and parcel of it." The court concluded that the defendants "ultimately failed to disentangle, as was their burden on the affirmative defense, what they say caused the losses from the very subjects of the material misrepresentations at issue."

What each side's expert must show

The defense economist. The defense expert carries the burden, and doubt is resolved against the defendant. The work usually includes:

  • The statutory measurement points: offering price, purchase and sale prices, and value at suit.
  • An event study of each disclosure date, controlling for market and industry movements, along the lines covered in Daubert Challenges to Event Studies. Akerman is a warning that raw comparisons to an index or to unrelated IPOs may not control for the variables that matter.
  • Evidence ruling out leakage before disclosure. Pre-disclosure declines generally may not be charged to defendants, but the burden stays with the defense.
  • A showing that the cause of the decline is unrelated to the subject of the misstatement. Nomura holds that a macroeconomic cause does not qualify if the concealed facts helped produce it.
  • Where the disclosure did not concern the offering documents, as in Britannia, an account of why the reaction reflects unrelated news.

The plaintiffs' expert. The plaintiffs' expert need not prove causation but must defend the statutory number and rebut the defense:

  • A damages calculation that applies Section 11(e) exactly, with the offering-price cap, the right measurement point for each share and only traceable shares.
  • A valuation for any claim that suit-date value differs from market price, which McMahan calls unusual and rare.
  • Evidence of how the truth got out, for any leakage theory. Akerman shows that the theory fails without it.
  • A critique of the defense model's controls, windows and any causes that overlap with the concealed facts.

What to prepare

  • The offering price, each tranche's effective date, and a schedule of registered shares by offering for tracing.
  • Daily prices from the offering through the date of suit and any later sales, with the date suit was first brought for each claim.
  • A per-share damages calculation under each of the three statutory measures, with the Section 11(g) and underwriter caps applied.
  • Event-study results for every disclosure date, with all same-day and nearby news identified.
  • A written attribution of each component of decline to the misstatement or to a specific unrelated cause, with the evidence for each.
  • If Section 12(a)(2) or 10b-5 claims are pleaded, a reconciliation of each decline under each statute.

The library's Section 11 negative causation economist page describes this class of expert and the methods it typically uses.

Supreme Mind builds Expert Witness AI Agents for litigation. A lawyer points an AI Agent at a matter and picks a class of expert, such as a Section 11 negative causation economist, and one run returns a brief in four sections: the expert's likely opinion, ranked cross-examination weaknesses, the Daubert and Rule 702 attack surface, and a directional settlement range. Experts are de-identified composites of a class, never a named individual, supporting quotations are checked verbatim against the public record, and nothing it produces is filed or testifies. A complete sample brief on In re Luckin Coffee is at /sample-brief, and the method is described at /method.

This guide is general information, not legal advice.

Sources

How each court of appeals applies amended Rule 702: see the Rule 702 tracker.

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Experts in this guide's practice

Defense event-study econometricianPlaintiff event-study and loss-causation econometricianMarket-efficiency expertSecurities accounting and GAAP expertSection 11 negative causation economist

The series

10Mass tort · October 20, 2026General Causation in Mass Torts: Bradford Hill Under Rule 70209Securities · October 19, 2026Section 11 Damages and Negative Causation08Antitrust · October 19, 2026Overcharge Regressions in Price-Fixing Cases07Antitrust · October 19, 2026How Often Courts Exclude Antitrust Economists, and Why06Securities · October 13, 2026Loss Causation, Damages and the Inflation Ribbon05Securities · October 6, 2026Market Efficiency at Class Certification: Cammer and Krogman04Any expert · September 29, 2026Amended Rule 702 After Nearly Three Years: What Courts Exclude03Antitrust · September 22, 2026Common Impact and Pass-Through at Class Certification02Securities · September 15, 2026Price Impact at Class Certification After Goldman01Securities · September 8, 2026Daubert Challenges to Event Studies in Securities Cases

Related: the expert agent library, a complete sample brief, and how it works.