Market Manipulation

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Over the past year, market-manipulation lawsuits have become a growing feature of the securities litigation landscape, with plaintiffs targeting alleged spoofing, short-selling, pump-and-dump schemes, and other trading-related misconduct. The latest such case, filed on July 31, 2026, in the Middle District of Florida, names hedge fund Pentwater Capital Management and its founder, Matthew Halbower, as defendants (Pentwater SCA). The complaint alleges that they manipulated the market for Avis Budget Group (Avis) shares by orchestrating a short squeeze and then selling into the resulting price spike.

Unlike pump-and-dump securities suits premised on allegedly false or misleading statements, the Pentwater SCA is based on the defendants’ trading activity itself. The lawsuit arguably represents an example of a growing trend in market-manipulation-related securities class action litigation while underscoring an increasingly important issue for D&O underwriters: securities litigation risk arising not from disclosure deficiencies, but from market-structure and trading-related factors capable of driving extreme stock-price volatility.

A copy of the Pentwater SCA can be found here.

Continue Reading Short Squeeze Lawsuit Filed Against Pentwater Capital

The wave of securities class actions alleging market manipulation involving recently public, low-float companies continues to grow. Notably, many of these lawsuits have involved non-U.S. companies that recently completed IPOs on U.S. exchanges. Two new pump-and-dump lawsuits, filed within a day of one another in the Southern District of New York against China-based iTonic Holdings Ltd. and Park Ha Biological Technology Co., Ltd., increase the number of market manipulation cases filed in 2026 to 13.

Continue Reading Pump-and-Dump Securities Suit Filing Trend Continues to Build

D&O Diary readers are aware of a growing trend over the past year: an increasing number of securities class actions arising from alleged market manipulation involving low-float public companies. These cases, ranging from pump-and-dump and spoofing schemes to stock promotion claims, now also include a lawsuit filed this week against Megan Holdings Limited (Megan), whose share price allegedly surged more than 400% in one month before plunging over 93% in a single trading day. The company, headquartered in Malaysia, develops, constructs, and maintains aquaculture farms and related infrastructure. 

Continue Reading Pump-and-Dump Securities Suit Adds to Growing Market Manipulation Litigation Trend

The third episode of The D&O Diary Podcast Series is now live. Building on our June 30, 2026, post discussing first-half federal court securities class action lawsuits, this episode explores the factors and  trends driving the number of current suit filings.

In this podcast, we discuss the overall increase in the total number of federal court securities suits during the first six months of 2026; the continued emergence of AI-related securities litigation; and the significant role that stock manipulation and promotion-related claims in the number of securities suits that have been filed so far this year. We also examine what these developments may mean for public companies, directors and officers, and D&O insurers in the months ahead.

Continue Reading The D&O Diary Podcast Series – Episode 3: Securities Class Action Suit Filing Trends

In the 2025 fiscal year (ended September 30, 2025), the SEC’s enforcement activity, as measured by the number of stand-alone enforcement actions, was at its lowest level in ten years. While the decline was reflected across many categories of SEC enforcement, there were certain specific areas – such as cases involving insider trading and market manipulation – where SEC activity actually increased. And notwithstanding the overall decline in SEC enforcement activity, there are signs to suggest that foreign companies listed on U.S. exchanges should be prepared heightened SEC scrutiny and enforcement activity, as discussed below.

Continue Reading SEC Enforcement Actions Decline, But Foreign Cos. Should Remain Vigilant

Short sellers have a complicated relationship to securities class action litigation, as several prior posts on this site have noted (most recently here). Among the more unusual roles short sellers can play in a securities suit is to serve as lead plaintiff. One recent high-profile case where a short seller acted as lead plaintiff is the suit filed against Overstock, its founder and former CEO, Patrick Byrne, and other executives. The short seller alleged, with some plausibility, that Overstock and Byrne had attempted to mount a “short squeeze” targeted at the short sellers. The district court granted the defendants’ motion to dismiss, and in an interesting October 15, 2024, opinion, the Tenth Circuit affirmed the district court. The appellate court’s opinion has several interesting features, as discussed below.

Continue Reading Tenth Circuit Affirms Dismissal of Short Seller’s Securities Suit Against Overstock