AI lawsuits surge to dominate securities class action filings in 2026
The Disclosure Dollar Loss (DDL) Index, which measures market cap changes at the end of a class period, rose 77% to $529 billion compared with the second half of 2025, approaching the all-time semiannual high of $544 billion set in the first half of 2022. AI-related filings alone accounted for $385 billion of that figure.
“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 Joseph Grundfest, Stanford Law professor and former Securities and Exchange Commission commissioner. “That imbalance highlights the extent to which a small number of high-impact matters can influence trends across securities litigation.”
The Maximum Dollar Loss (MDL) Index — which captures the peak-to-end market cap decline during a class period — reached $1.858 trillion in the first half of 2026, nearly triple the historical semiannual average of $667 billion. Just two of the 15 AI-related filings accounted for $1.235 trillion, or 66%, of the entire MDL Index for the period.
Technology sector filings climbed from nine in the second half of 2025 to 24 in the first half of 2026, driven in part by a surge in AI-related complaints within the sector. The sector comprised 78% of the DDL Index for the period despite representing only 21% of core filings — a concentration that signals significant litigation exposure for the large-cap tech names that dominate many client portfolios. Advisors monitoring risk at the portfolio level may find it worth reviewing [how securities litigation trends affect wealth management strategy](https://www.investmentnews.com) for their clients.
The pump-and-dump category itself emerged as a notable trend beginning in November 2025. A total of 10 such complaints have been filed since then — two in late 2025 and eight in the first half of 2026 — with nine of those 10 targeting non-U.S. issuers and filed in the Second Circuit. That geographic and issuer concentration may carry implications for advisors with exposure to smaller-float international equities.
