Top Kalshi trader Caleb Davies usually speaks to the press about how prediction markets help him rake in money. The Minneapolis-based IT worker estimates he’s made $1.2 million overall across different prediction platforms, with $414,000 in winnings from Kalshi’s culture markets alone. He especially enjoys wagering on music charts, because he carefully analyzes Spotify data to pick winners. “Every single morning, I’m going in, downloading the data, and updating my projections,” he tells WIRED.

This summer, though, he’s become increasingly agitated about what he claims is an obvious, bot-fueled effort to manipulate Spotify-related markets. He recently began compiling and publishing evidence for his theory, eventually becoming so convinced that he contacted Spotify, Kalshi, and Polymarket with his concerns.

This week, the situation hit a boiling point when the song “Earrings” by Malcolm Todd surged to number one on a Spotify chart. In a series of X posts, Davies outlined his suspected culprit: “botting,” or scammers who purchase bots to juice streaming numbers. Davies argued that prediction market traders were botting the charts to influence the outcome of related events contracts. Todd’s song was such an underdog that it wasn’t even listed as an option on Polymarket: “Looking at the dataset of Sunday to Monday changes, it was a 11.24 sigma event, or a roughly 1 in 77 octillion chance of happening randomly,” Davies wrote.

It turns out that he was on to something. Spotify confirmed to WIRED that it investigated suspected manipulation incidents Davies flagged and found evidence of artificial streaming. “All streaming services face ever-changing stream manipulation. Spotify has best-in-class detection and mitigation practices for manipulated streams, and we don’t pay out associated royalties,” spokesperson Laura Batey says. (The company didn’t offer any explanation for the manipulation, however, so Davies’ theory that it was directly tied to a scheme to manipulate prediction markets remains just that.)

Spotify ultimately adjusted its charts to account for the discrepancy, culling over 500,000 artificial streams, which bumped Todd’s song from first to fourth. The process was not immediate, though, and Kalshi had already resolved the market to award traders who selected Todd’s song.

“We're in touch with Spotify and are actively investigating this matter,” Kalshi spokesperson Elisabeth Diana tells WIRED. Those conversations did prompt a more immediate change: At the Swedish streaming giant’s request, Kalshi removed Spotify’s logo from its markets that relate to the company, and adjusted language that initially suggested Spotify had verified chart results.

When Davies first reached out to Kalshi with concerns, the company’s head of enforcement Robert DeNault told the trader that only Spotify would be able to definitively confirm whether it had been botted, and noted that there could be non-suspicious reasons for the uptick. DeNault also floated a theory that Kalshi traders could be merely copying what peers were doing on Polymarket.

“Nobody from Polymarket profited from the fraud. That’s what undermines Kalshi’s argument, because they didn’t have a Malcom Todd bracket,” Davies tells WIRED.

Polymarket refutes this theory as well. “It’s actually not plausible since we didn’t even have Malcolm Todd as an option on this Spotify market,” said spokesperson Annabel Walsh. The company confirmed it’s reviewing the broader streaming manipulation situation, but hasn’t identified any immediate manipulation thus far.

No one has spoken with the people or group of people behind the streaming manipulation, so their motivations remain unclear. (Todd did not respond to requests for comment, but there’s nothing to suggest he’s anything more than an innocent bystander.)

What is clear is that this type of market introduces a new incentive for streaming fraudsters. This year, several high-profile arrests have been made related to alleged insider trading schemes on Polymarket, though none have been tied to streaming charts.

“The platforms are not supposed to list contracts at all, unless they make an affirmative determination that they are not readily susceptible to manipulation. It is clear that in this market, and many other markets, they are not doing that,” says Amanda Fischer, a former Securities and Exchange Commission chief of staff and the policy director and chief operating officer of the Wall Street watchdog nonprofit Better Markets. “They’re obviously readily susceptible to manipulation.”

As for Davies, for now, he’s swearing off chart-based markets. “They've been a big gainer for me historically, but I can't play it anymore,” he says.