BacktestFolio · Glossary
Trinity Study
In plain language
The origin of the 4% rule: the study showed that, over 30 years, an annual withdrawal of 4% of initial capital has historically had a high probability of success for balanced equity/bond portfolios.
Technical definition
Academic study from 1998 (Cooley, Hubbard, Walz — Trinity University) which, by analysing historical US market data, identified «safe» withdrawal rates for accumulation/decumulation portfolios, popularising the '4% rule'.