If you own stocks, 2025 delivered a paradox worth understanding: companies were sued less often than the year before, yet the market value wiped out in those cases hit an all-time high. Here is what the annual scorecard actually says — and what it does not.
The Headline: Fewer Cases, Bigger Losses
Plaintiffs filed 207 new securities class actions in 2025, down from 226 in 2024 — an 8% decline. Almost all of the drop came in the second half of the year, with 114 filings in the first half of 2025 and just 93 in the second half. By count, it was the quietest year for core filings since 2014.The dollar side moved in the opposite direction. Disclosure Dollar Loss, or DDL, rose to a record $694 billion, up from $429 billion in 2024 — an increase of roughly 62%. Maximum Dollar Loss, or MDL, climbed 75% to $2,862 billion, its third-highest reading on record. Two indices that measure lost market value both surged in a year when the case count fell. The median case grew too: median DDL reached a record $503 million.
The reason those two things can happen at once is that the dollar indices do not count lawsuits. They measure how much market value evaporated in the companies that were sued. A handful of giant cases can lift the totals even as the overall number of cases shrinks.
Why the Dollars Exploded: Mega Filings
The engine behind the record was a small group of enormous cases that Cornerstone Research calls mega filings — those with a Disclosure Dollar Loss of at least $5 billion or a Maximum Dollar Loss of at least $10 billion.In 2025, mega filings accounted for 89% of total MDL and 81% of total DDL, well above their long-run averages of 80% and 65%. There were only 36 mega MDL filings, roughly the same as 2024's 34, but the total MDL tied to them jumped 97%, from $1,292 billion to $2,551 billion. In other words, the year's litigation losses were highly concentrated in a few very large companies. Strip those out and 2025 looks like an ordinary, even slow, year.
This concentration is why a "record loss" headline can be misleading on its own. A single case against a trillion-dollar company can move a national statistic more than a hundred cases against small ones.
Artificial Intelligence Was the Year's Big Theme
The trend categories with the most filings in 2025 were artificial intelligence (16), SPACs (10), and cryptocurrency (9). AI narrowly edged out its 2024 count of 15, but the timing was striking: 12 of the 16 AI-related cases were filed in the first half of the year, and only four in the second half.What makes AI stand out is not the count but the size. AI-related filings were only about 8% of core filings, yet they accounted for 57% of the entire Maximum Dollar Loss Index for the year. That is mega-filing concentration in a single theme: a few suits against very large AI-exposed companies drove a disproportionate share of the market value at stake. The Technology sector overall told a similar story — filings there actually fell from 37 to 30, but total MDL for technology cases rose 260%, from $347 billion to $1,250 billion.
SPACs, Crypto, and the Near-Disappearance of COVID Cases
Cryptocurrency filings ticked up from seven in 2024 to nine in 2025. SPAC filings eased slightly to 10, a shadow of the SPAC-litigation wave of 2021 through 2023, when annual counts ran into the high twenties and thirties.The clearest fade was COVID-19. Pandemic-related securities cases fell from 15 in 2024 to just three in 2025, the fewest since the clearinghouse began tracking the category in 2020. Across every filing cohort since 2021, Cornerstone Research reports, COVID-related cases have been dismissed at a higher rate than other securities suits — a category that is now largely working its way out of the courts.
Who Got Sued: Sectors and Courts
The odds of getting sued eased slightly. The likelihood of a core federal filing against a U.S. exchange–listed company slipped from 3.9% in 2024 to 3.5% in 2025. Among S&P 500 companies, 5.8% faced a core federal filing, down modestly from 6.1%.Lawsuits against foreign companies fell sharply. Filings against non-U.S. issuers dropped 35%, from 34 to 22, and as a share of all core federal filings they hit an 11% level — a 15-year low. By region, the number of cases in the Ninth Circuit (which covers California) fell 30%, from 69 to 48. The Third Circuit bucked the trend, rising from 19 to 26 on a surge of biotechnology and pharmaceutical cases. And the Consumer Cyclical sector — think retail and autos — saw filings drop by nearly half.
IPOs and the Quiet 1933 Act Corner
Not every securities case is a fraud claim under Rule 10b-5. A separate slice arises under the Securities Act of 1933, which lets investors sue over misstatements in the registration documents for stock offerings, including IPOs. These cases can be filed in federal or state court.Combined federal and state 1933 Act filings edged up to 23 in 2025 from 22 in 2024. State-court 1933 Act activity stayed very low, with only four such filings all year. Meanwhile the IPO market reopened: operating-company IPOs on major U.S. exchanges rose 25% to 234, and SPAC IPOs jumped from 57 to 144. Because it typically takes months for an offering to draw a lawsuit — the median lag between an IPO and a Section 11 or 1933 Act filing was 308 days — a busier IPO year can seed litigation that shows up later. Share-price disappointments like the $740 million DiDi IPO securities settlement are the kind of case this corner of the docket produces.
Two Legal Developments Worth Watching
The report also flagged two 2025 developments that could shape how these cases run.In In re FirstEnergy Corp. Securities Litigation, the Sixth Circuit on August 13, 2025 vacated a district court's order certifying a class of investors who alleged the company concealed its involvement in a bribery scheme. The appeals court held that the case, built on a mix of misrepresentations and omissions, had to be analyzed under the Basic v. Levinson reliance framework rather than the more plaintiff-friendly Affiliated Ute presumption, and that the lower court had not performed the rigorous damages analysis the Supreme Court requires. Those allegations remain unproven, and the case was sent back for further review.
Separately, on September 17, 2025 the Securities and Exchange Commission issued a policy statement signaling that a company's inclusion of a mandatory-arbitration provision for investor claims would not, by itself, block the SEC from accelerating a registration statement. If issuers begin adding such clauses, it could — over time — change how, and whether, some investor disputes reach a courtroom at all.
What It Means for Everyday Investors
A few takeaways cut through the numbers. First, a record "loss" figure is a measure of scale, not guilt. Cornerstone Research is careful to note that DDL is not an indicator of liability or a measure of damages — a stock can fall for reasons that have nothing to do with the allegations. Second, most securities cases do not end in a payout: from 1997 to 2025, roughly 46% of core federal filings settled and about 45% were dismissed, so a filing is a starting point, not a conclusion.And third, if you are ever an eligible class member in one of these cases, the money usually turns on documentation. Unlike the broad consumer settlements where anyone can file, securities settlements generally pay based on your trades during the class period and require brokerage records — as the open Estée Lauder securities settlement shows. We track the ones with active claim windows on our securities class action settlements page.
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Frequently Asked Questions
How many securities class actions were filed in 2025?
Plaintiffs filed 207 new securities class actions in 2025, down from 226 in 2024, according to Cornerstone Research's 2025 Year in Review prepared with the Stanford Law School Securities Class Action Clearinghouse. The decline was concentrated in the second half of the year: there were 114 filings in the first half of 2025 and only 93 in the second half.
Why did investor losses set a record if fewer cases were filed?
The dollar indices measure the market value wiped out in the companies that were sued, not the number of lawsuits. In 2025, a small number of very large cases, called mega filings, drove the totals. Mega filings accounted for 89% of total Maximum Dollar Loss and 81% of total Disclosure Dollar Loss. So even with fewer cases overall, the presence of several giant cases pushed Disclosure Dollar Loss to a record $694 billion.
What is Disclosure Dollar Loss (DDL)?
Disclosure Dollar Loss is the drop in a company's market value between the trading day before the end of the alleged class period and the trading day after it. It estimates the market reaction to whatever information came out at the end of the class period. Cornerstone Research is explicit that DDL is not a measure of liability or of potential damages, because a stock can fall for many reasons unrelated to the allegations. It is a scale indicator, not a verdict.
Were AI companies a big driver of securities litigation in 2025?
Yes, by dollar value. There were 16 AI-related filings in 2025, only slightly more than the 15 in 2024, and they were front-loaded, with 12 in the first half and just four in the second half. But AI-related filings made up only about 8% of core filings while accounting for 57% of the total Maximum Dollar Loss Index, because several involved very large companies.
Does a securities class action filing mean a company did something wrong?
No. A filing is an allegation, not a finding. Many securities class actions are dismissed, and others settle without any admission of wrongdoing. Cornerstone Research reports that from 1997 to 2025, about 46% of core federal filings were settled and about 45% were dismissed. A large market value drop that drives a big Disclosure Dollar Loss figure does not establish that the company violated the securities laws.
Who publishes the Securities Class Action Filings Year in Review?
The report is published by Cornerstone Research in collaboration with the Stanford Law School Securities Class Action Clearinghouse. It has tracked federal securities class action filings since the Private Securities Litigation Reform Act took effect in the 1990s and now includes state 1933 Act filings as well. OpenClassActions.com is summarizing that research, not conducting it.
Sources
• Cornerstone Research, "Securities Class Action Filings—2025 Year in Review" (in collaboration with the Stanford Law School Securities Class Action Clearinghouse)• Stanford Law School Securities Class Action Clearinghouse
• In re FirstEnergy Corp. Securities Litigation, No. 23-3940 (6th Cir. Aug. 13, 2025)
• U.S. Securities and Exchange Commission, Policy Statement, "Acceleration of Effectiveness of Registration Statements of Issuers with Certain Mandatory Arbitration Provisions," Rel. Nos. 33-11389, 34-103988 (Sept. 17, 2025)
