Kalshi has enlisted Lionel Messi and Timothée Chalamet as prediction markets compete to attract new users and cement their place in the mainstream.

Getting the future right is now big business. But at a festival in Berkeley, forecasters worry that sports markets could take the whole industry down.

Kalshi has enlisted Lionel Messi and Timothée Chalamet as prediction markets compete to attract new users and cement their place in the mainstream.