Charles Ponzi

Italian-American fraudster who defrauded investors in Boston in 1919–1920 by promising 50% returns in 90 days through international postal reply coupon arbitrage — which was impossible at scale — creating the scheme that now bears his name.

Gave his name to the most common fraud structure in history — using new investor money to pay old investors while claiming returns from a legitimate arbitrage — making the Ponzi scheme the canonical example of the fraud that is structurally impossible to sustain but psychologically irresistible to join.