Retirement Planning Insights

Expert analysis on historical simulation, withdrawal strategies, and financial independence planning

Historical 90% and Monte Carlo 90% Are Not the Same Number

Methodology Bellavia Research

Historical 90% and Monte Carlo 90% Are Not the Same Number Even when both say 90% success and displayed the same way, they do not …

Jan 30, 2026 10 min

Monte Carlo vs Historical Simulation: Why They Disagree and Why That's Fine

Methodology Bellavia Research

You ran a retirement simulation and got two results. The historical backtest says 98.9% success. The Monte Carlo says 90.5%. Which one is right? Both. …

Jan 15, 2026 7 min