With the US midterms fast approaching, voters and the media are increasingly looking to a new forecasting tool: prediction markets.

The leading platforms, Kalshi and Polymarket, have been touted as a truth serum for political forecasting — arenas for mass betting that reveal what people really think when they’ve got money on the line. But a new Bloomberg investigation has found evidence that these markets are vulnerable to manipulation.

On today’s Big Take podcast, host Sarah Holder and Bloomberg investigative reporter Liam Vaughan dig into what can happen when prediction markets mix with politics — and how cheap and easy it can be to sway them.

Read more: How a Few Hundred Dollars Could Manipulate Election Prediction Markets

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Hosted by Sarah Holder; Produced by Victor Swezey and David Fox; Reported by Liam Vaughan; Edited by Tracey Samuelson.

Fact-checking by Julia Press; Engineering by Alex Sugiura.

Senior Producer: Naomi Shavin; Deputy Executive Producer: Julia Weaver. Executive Producer: Nicole Beemsterboer.