Coinbase CEO Stunt Exposes Prediction Market Vulnerability (1)

When Coinbase Global Inc.’s quarterly earnings call wrapped up Thursday, its chief executive, Brian Armstrong, didn’t finish with profit guidance or statements of confidence. He closed it out with a list: “Bitcoin, Ethereum, blockchain, staking and Web3.”

Those weren’t random buzzwords. They were part of an $84,000 betting market.

Across prediction market platforms Kalshi and Polymarket, users had wagered on which words would be spoken during the call — part of a niche category known as mention markets, where the outcome isn’t tied to earnings, price moves or sports games, but to what people say in some public ...