Shares of AppLovin tumbled 13% Wednesday as two short-seller reports cast doubt on the integrity of the company’s AI-powered AXON advertising software that helped drive the tech giant to become the top-performing tech stock of 2024.

Short seller Fuzzy Panda alleged that the AXON model was “the nexus of a House of Cards” built on fraudulent advertising tactics.

“We believe AppLovin has pulled every trick in the book,” the post stated. “We’ve been told they are stealing data from Meta in their e-commerce push. We also discovered AppLovin exploiting consumers and their data in ways which are clear violations of Google and Apple’s app store policies.”

The reports from Fuzzy Panda and Culper Research come following a stellar fourth-quarter earnings beat in February that kept Wall Street feeling bullish on AppLovin. CEO Adam Foroughi announced the company would spin off its mobile gaming segments and continue expanding the AXON model to other e-commerce sectors, like health care, automotive and more. AppLovin’s advertising revenue climbed 73% in the quarter to reach almost $1 billion. 

It wasn’t clear if Fuzzy Panda and Culper Research were still short on AppLovin at the time of publication, and neither firm immediately responded to a request for further comment.

AppLovin did not immediately respond to a request for comment.

This is a developing story. Please check back for updates.