Shayne Coplan (born 1998) is an American entrepreneur, technologist, and the founder and chief executive officer (CEO) of Polymarket, a prediction market.^[1][2] In October 2025, he became the world's youngest self-made billionaire according to the Bloomberg Billionaires Index, with a net worth of $1.0 billion according to Forbes.^[3]

Shayne Coplan was born in 1998 and raised on the Upper West Side of New York City to a Jewish family.^[1][4] He attended public schools in Hell's Kitchen.^[1] Coplan studied computer science at New York University but left before completing his degree to pursue interests in cryptocurrencies and prediction markets.^[1][4]

In 2014, Coplan participated in the initial coin offering of Ethereum and acquired the cryptocurrency when it was priced significantly lower than its later value.^[1][4] Inspired by economist Friedrich Hayek’s theories on decentralized information systems and George Mason University professor Robin Hanson’s work on Futarchy, Coplan founded Polymarket in 2020, which operates as a prediction market using smart contracts on the Polygon blockchain for settling wagers.^[1][4] Coplan’s Polymarket is now the largest prediction market in the world, facilitating over $3.2 billion in bets during the 2024 United States presidential election and featuring prominently in mainstream media coverage of the election. He was raided by the FBI in November 2024.