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Glossary entry · Money in motion

Trinity Study

Definition

A 1998 study by three Trinity University professors (Cooley, Hubbard, and Walz) that simulated 30-year retirements starting in every year from 1926 onward, using a 60/40 stock-bond portfolio. They counted how many starting points survived various withdrawal rates. The 4% line survived ~96% of scenarios, the foundation of every "safe withdrawal" conversation since.

Example

Withdrawing 7% per year survived only ~30% of historical scenarios in the Trinity Study; 4% survived nearly all.