Before damages are counted, two economic showings gate the case: that the market price reflected information, and that the loss came from the truth coming out.
Start a conversation with Cournot, the Institute’s damages concierge, already scoped to loss causation & market efficiency. Pick a starting point, or describe the dispute directly.
Securities litigation delegates two of its threshold questions to economics. The first is efficiency: whether the security traded in a market that rapidly impounds public information, which is what justifies treating the market price as the medium through which every class member relied. The showing is empirical and conventional, built from trading volume, analyst and institutional following, spreads and float, and, most persuasively, direct evidence that prices responded to news, which is an event study finding. The second is loss causation: the decline for which damages are sought must trace to the revelation of the concealed truth, not to the market falling, the sector rotating, rates moving, or the company disclosing unrelated bad news the same afternoon. This is disaggregation under another name, practiced at daily frequency with unusually good data, and it is where most securities damages cases are actually won or lost. Between the two sits price impact, the question of whether the alleged misstatements affected the price at all, which defendants may contest directly, and which has its own asymmetry: a misstatement can matter not by inflating the price when made but by maintaining inflation that was already there, confirming the market's mistaken belief rather than creating it. The price maintenance pattern complicates the naive test, no front-end price bump means no impact, and the argument over what the absence of a back-end reaction proves is among the most active in the field. The doctrinal architecture, presumptions, burdens, what suffices at which stage, is counsel's. The empirical work underneath is not optional, and its quality is usually dispositive.
Efficiency lets the case proceed as a class. Causation decides what the class can recover.
Volume, coverage, ownership, spreads, float, and news responsiveness. A cumulative showing, with the last factor doing the real work.
Whether the misstatements affected the price, at the front end or by maintaining existing inflation. Contested directly in modern practice.
Confirmatory lies that keep an inflated price inflated. No reaction when made, full reaction when corrected.
When and how the concealed truth reached the market: one clean revelation, or a series of partial ones, each contested.
Market, industry and company-specific causes separated from the fraud’s share of each decline.
Losses framed as a concealed risk coming true rather than a lie corrected. A distinct causal theory with its own proof pattern.
How the Institute approaches the causal showings.
These are gates. Cases end here in both directions.
A stock that fell hard on the disclosure day fell for every reason present that day: the revelation, the market, the sector, the guidance cut announced in the same release. The recoverable share is what remains after honest disaggregation, and the expert who does that work first controls the frame the tribunal sees.
Demonstrated cause and effect, above everything else on the list. The structural factors, volume, analyst coverage, institutional ownership, tight spreads, large float, establish that the conditions for efficiency were present, and they are necessary but rarely disputed territory for a large-cap stock. The showing that does the work is dynamic: an event study across the class period demonstrating that the price responded promptly and directionally to new material information, earnings surprises moving the price, guidance changes moving it, with the relationship statistically established. For smaller, thinner securities the structural factors become genuinely contested, and the dynamic showing becomes both harder and more important. An efficiency opinion reciting factors without testing responsiveness is the weak version, and opposing experts treat it accordingly.
It breaks the symmetry between the front end and the back end of the alleged fraud. The naive test says: if the misstatement mattered, the price should have jumped when it was made. Price maintenance answers: a statement that falsely confirms what the market already believes produces no front-end movement at all, because it tells the market nothing new; its effect is preserving inflation that would otherwise have drained out, and the evidence of that effect is the reaction when the truth finally emerges. The economic debate is then about what the back-end reaction proves and whether the counterfactual, the price falling earlier absent the confirmation, can be established. Defendants press the absence of front-end impact; plaintiffs press the back-end decline. The expert's contribution is disciplining both inferences with evidence about what the market believed and when.
Because the truth rarely arrives in one press release, and every intermediate step is arguable. Real revelations leak: a short-seller report the company denies, an unexplained executive departure, an announced investigation, restated guidance, and finally the restatement itself. For each candidate disclosure the questions compound: did it actually reveal a portion of the concealed truth, or merely new bad news; how much of the concealed information did it convey; and did the market understand it as corrective at the time, which analyst commentary and press coverage evidence. The allocation matters because damages accrue disclosure by disclosure, and class period boundaries and inflation series follow from it. This is where the disclosure chronology work earns its cost: the side that has actually mastered what the market knew, date by date, wins most of the marginal arguments.
With the same control machinery the event study uses, applied to the damages arithmetic. The market model already nets out the expected return from market and industry movements on each disclosure day, so a properly built abnormal return has, by construction, removed the environment's share of that day's decline. The remaining fights are about what the controls miss: company-specific bad news unrelated to the fraud on the same day, which needs the confound analysis; industry indices that themselves contain the defendant or its co-movers, which circularly absorb the fraud's effect; and longer windows where the environment's influence compounds. In prolonged declines, plaintiffs' and defendants' experts often present dueling decompositions of the same fall, and the one built from a stated, pre-committed method rather than a date-by-date narrative tends to survive scrutiny better.
Describe the security and the timeline. The Institute will help you see where the causal showing will be won or lost.