Overall Size of Securities Class Action Filings Reached New Heights in 2025

DDL and MDL dramatically increased as number of filings declined for first time in two years.

MENLO PARK, Calif., Jan. 28, 2026 /PRNewswire/ -- The number of securities class action filings decreased for the first time in two years in 2025, while the overall size of filings increased substantially, according to a report released today by Cornerstone Research and the Stanford Law School Securities Class Action Clearinghouse, which was supplemented with data from Stanford Securities Litigation Analytics. The report, Securities Class Action Filings—2025 Year in Review, found that plaintiffs filed 207 securities class actions in federal and state courts in 2025, a decline from 226 in 2024.

Key Findings

• The size of securities class action filings was significantly larger in 2025 than in 2024, with the Disclosure Dollar Loss (DDL) and Maximum Dollar Loss (MDL) sharply increasing to the highest and third highest on record, respectively.
• Core filings—those excluding M&A filings—totaled 201, a decrease from 221 in 2024.
• Artificial intelligence (AI)-related filings slightly increased, with 16 filings in 2025, although only four were filed in the second half of the year.
• Mega filings accounted for the vast majority of total MDL and total DDL (89% and 81%, respectively), significantly above the 1997–2024 annual averages (80% and 65%, respectively).

"The decrease in overall filing volume was largely driven by a decline in filing activity in the second half of 2025, with 93 filings in 2025 H2 compared to 114 filings in 2025 H1," said Alexander "Sasha" Aganin, the report's coauthor and a Cornerstone Research senior vice president, who coheads the firm's finance practices. "Total Disclosure Dollar Loss, meanwhile, has set an all-time record."

The Disclosure Dollar Loss increased from $429 billion in 2024 to $694 billion in 2025. The Maximum Dollar Loss similarly increased to $2,862 billion in 2025 from $1,639 billion in 2024, an increase of 75% and the third-highest level on record. While the number of mega filings (36) was only slightly higher than that of 2024 (34), total MDL from mega MDL filings in 2025 ($2,551 billion) increased by 97% relative to 2024 ($1,292 billion).

"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," according to Joseph Grundfest, former SEC Commissioner and Stanford Law Professor (emeritus). "The market should also watch the SEC's enforcement agenda. 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."

Read the full report here. 

About Cornerstone Research
Cornerstone Research provides economic and financial consulting and expert testimony in all phases of complex disputes and regulatory investigations. The firm works with an extensive network of prominent academics and industry practitioners to identify the best-qualified expert for each assignment. With a reputation for high quality and effectiveness, Cornerstone Research has consistently delivered rigorous, state-of-the-art analysis since 1989. The firm has more than 1,000 professionals in nine offices across the United States, UK, and EU. 

About Stanford Securities Litigation Analytics and the Stanford Law School Securities Class Action Clearinghouse
Stanford Securities Litigation Analytics (SSLA) and the Securities Class Action Clearinghouse (SCAC) are authoritative sources of data and analysis on the financial and economic characteristics of federal and state securities fraud class action litigation. Data from the Securities Class Action Clearinghouse has been supplemented with data from Stanford Securities Litigation Analytics to identify 7,070 federal securities class action filings between January 1, 1996, and December 31, 2025. The analysis in this report is based on data identified as of January 9, 2026.

SOURCE Cornerstone Research