Duolingo Faces Shareholder Class Action Over Disclosures on AI Backlash and DAU Growth

What the lawsuit challenges

The Exchange Act action is pending in the U.S. District Court for the Western District of Pennsylvania. According to the SueWallSt release, which is powered by the law firm Levi & Korsinsky LLP, the complaint questions whether Duolingo's shareholder letters, Forms 10-Q and earnings calls disclosed that ad-heavy monetization, the Energy feature and mass-produced AI content were eroding daily active user (DAU) growth.

The release says Duolingo shares lost a combined $97.65 per share across three disclosure days and closed at $101.00 on February 27, 2026. It adds that the complaint asserts investors suffered billions of dollars in losses. These are claims made by the plaintiffs' side and have not been tested in court.

The statements at issue

The release points to several statements by Duolingo. In its second-quarter 2025 shareholder letter, the company said DAU growth reflected its "ability to continuously improve our app." The letter also credited Energy with lifting DAUs, learning time and subscriber conversion, saying: "We have rarely seen a feature move more than one of these metrics, let alone all three."

On the August 6, 2025 earnings call, management said it did not believe the AI backlash was "very material in terms of when you're looking at actual financial metrics." Management also said the company "typically only guide[s] to DAU whenever there's going to be a big change."

What the complaint alleges was left out

The complaint argues those statements were materially incomplete. According to the release, it alleges the following omissions:

• Energy drained a free user's balance with each correct answer, a design plaintiffs say was aimed at forcing paid conversions.
• The company's thousands of A/B tests showed added friction was depressing DAU growth rates.
• Unskippable ads after each lesson pushed some users to abandon years-long streaks.
• Rapidly generated AI content brought translation errors, pronunciation errors and repetitive lessons, even in the premium Max tier.
• The DAU slowdown extended beyond the AI-memo backlash and was expected to persist alongside the monetization push.

Plaintiffs also contend that generic cautionary language cannot shield statements about risks allegedly already visible in the company's own test data. The release notes that management again declined to guide DAUs in November 2025, yet preliminary figures in January 2026 put DAU growth at 30% and the February 26, 2026 results guided 2026 growth to just 20%. According to the complaint, management then acknowledged deliberately introducing "friction" into the free user experience.

What it means for investors

The release says the complaint names Duolingo and individual defendants, including senior executives who signed SEC filings or made public statements. Investors who bought during the class period may be eligible to take part, and the release states that eligibility depends on when shares were purchased, not on whether they are still held. It says no immediate action is required to remain eligible as an absent class member, though those wishing to seek the lead plaintiff role face the December 7, 2026 deadline.

The release also says securities class actions typically take two to four years from filing to resolution, depending on court scheduling and whether the case is dismissed, settled or litigated further. The document is attorney advertising, and it notes that prior results do not guarantee similar outcomes. The allegations are unproven, and the source contains no response from Duolingo.