The volume of U.S. securities class action activity declined in 2025, but the potential size of those claims soared, according to data from Cornerstone Research and the Stanford Law School Securities Class Action Clearinghouse.
In a report released Tuesday, they revealed that there were 207 securities class actions filed in federal and state courts in 2025, down from 226 filings the previous year. Excluding M&A-related filings, the number of core filings was also down to 201 last year from 221 in 2024.
This was the first time the number of securities class actions declined in two years, it noted.
“The decrease in overall filing volume was largely driven by a decline in filing activity in the second half of 2025,” said Alexander Aganin, senior vice-president at Cornerstone Research and co-author of the report, in a release — noting that there were 93 filings in the second half, down from 114 in the first half.
One area where filings increased last year was cases related to AI, such as claims of AI-washing, the report noted, although only four of the 16 AI-related cases came in the second half.
The number of crypto-related filings also ticked up to nine in 2025 from seven a year prior, but that’s down from 23 in 2022. Pandemic-related filings dropped to three from 15, and the number of cases involving SPAC deals was down to 10 last year from an average of 30 cases for the 2021–2023 period.
Despite the decrease in the number of class actions, the size of those cases — the alleged losses covered by the cases — jumped significantly, the report said.
According to the data, the disclosure dollar loss — the change in market cap for class-action targets between the day before and day after the end of the class-action period — increased to US$694 billion last year from US$429 billion in 2024.
At the same time, the maximum dollar loss — the change in market cap from a company’s highest stock price during the class period to the day after the class period — jumped to $2.9 trillion from US$1.6 trillion.
“The sharp increase in the disclosure and maximum dollar loss metrics is the big news, because it suggests large future settlement values. The larger dollar amount at issue is far more important than the modest decline in the number of companies sued,” said Joseph Grundfest, emeritus law professor at Stanford.
“The market should also watch the SEC’s enforcement agenda,” Grundfest said. “Private litigation sometimes rides on SEC enforcement coattails. So, if the SEC sues fewer issuers, those coattails are shorter and fewer public companies will experience a ‘me-too’ private litigation effect.”