Securities Class Action Filings Surge in the First Half of 2026

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AI-related filings on pace to nearly double 2025 levels.

Securities class action filings increased 30% to 121 during the first half of 2026 relative to the prior six months, which coincided with a surge in litigation involving artificial intelligence-related claims and technology companies. A new report released today by Cornerstone Research and the Stanford Law School Securities Class Action Clearinghouse, supplemented with data from Stanford Securities Litigation Analytics, highlights historical and recent filings activity, characteristics, and trends.

The report, Securities Class Action Filings—2026 Midyear Assessment, found that investors filed 15 AI-related securities class action lawsuits during the first half of 2026, putting such filings on pace to nearly double the 2025 total. Meanwhile, cryptocurrency (three filings) is on pace to be the lowest since 2019; there have been no COVID-19 or cybersecurity filings so far this year.

Primarily fueled by AI-related concerns, filings targeting the technology sector increased from nine to 24.

“Data from the first half of 2026 point to several notable shifts in securities class action filings,” said Alexander “Sasha” Aganin, coauthor of the report, Senior Vice President at Cornerstone Research, and cohead of the firm’s finance practices. “Primarily fueled by AI-related concerns, filings targeting the technology sector increased by 15 filings, from nine to 24. At the same time, core federal filings against non-U.S. issuers rose sharply, driven by complaints alleging ‘pump-and-dump’ schemes. Filings against companies headquartered outside the United States are on pace to reach 46 this year, twice that of those filed in 2025.”

Securities Class Action Filings—2026 Midyear Assessment

Along with the increase in filings, the overall size of alleged investor losses increased as well. Disclosure Dollar Loss (DDL), which measures the market cap change at the end of a class period, rose significantly. The 77% increase in the DDL Index was largely driven by AI-related filings, which accounted for 73% of the total DDL in 2026 H1.

AI-related cases represented a modest share of total filings but an outsized share of alleged investor losses in the first half of 2026.

The Maximum Dollar Loss (MDL), which measures the change in market capitalization from the peak during the class period to the end, rose to nearly triple the historical semiannual average, supported by the high market value losses of companies involved in AI-related litigation.

“AI-related cases represented a modest share of total filings but an outsized share of alleged investor losses in the first half of 2026,” said Stanford Law Professor and former SEC Commissioner Joseph Grundfest. “That imbalance highlights the extent to which a small number of high-impact matters can influence trends across securities litigation.”

Additional Key Trends
  • AI-related filings represented 13% of core filings, but DDL from these filings ($385 billion) accounted for 73% of the DDL Index in 2026 H1 ($529 billion).
  • Five of the 17 Mega MDL filings in 2026 H1 were AI-related; 80% of Mega MDL was from AI-related filings.
  • The DDL Index rose 77% compared to 2025 H2, due in part to increased filing activity as well as a 12% increase in median DDL compared to 2025.
  • The Second and Ninth Circuits continue to be the primary venues, accounting for 70% of the number of core federal filings.
  • Filing activity was concentrated in the first quarter, with 69 filings in Q1 compared to 52 in Q2.
  • Combined federal Section 11 and state 1933 Act filing activity was in line with prior years. Federal M&A class action filing activity remained low with only four filings.
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 7,073 federal securities class action filings between January 1, 1996, and June 30, 2026. The analysis in this report is based on data identified as of July 11, 2026.