Retirement Planning Insights

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

GK Guardrails Explained: How the 2006 Decision Rules Actually Work

GK Guardrails Explained: How the 2006 Decision Rules Actually Work

Compare Bellavia's two guardrail withdrawal strategies — parametric (user-set 3%/5% bands) and canonical Guyton-Klinger 2006 (four fixed rules) — across 91 historical cohorts. Includes a …

18 min
Maximum Withdrawal Rate: 4%, 5%, or 6%? 150 Years of Evidence

Maximum Withdrawal Rate: 4%, 5%, or 6%? 150 Years of Evidence

The 1966 retiree could safely withdraw 3.9% annually (adjusting for inflation). The 1982 retiree could safely withdraw 11.8%, a full three times more spending power …

8 min
Sequence of Returns Risk Calculator: Early Years Matter Most

Sequence of Returns Risk Calculator: Early Years Matter Most

When planning for retirement, small differences in withdrawal rates can have dramatic impacts on portfolio longevity. This analysis explores what happens when you increase your …

12 min
How Long Will $1M Last? We Tested Every Year Since 1871

How Long Will $1M Last? We Tested Every Year Since 1871

Type "how long will $1 million last in retirement" into Google. You'll get a dozen articles all saying the same thing: "it depends" or "25-40 …

15 min
The 4% Rule Is Wrong: What the Creator Now Recommends

The 4% Rule Is Wrong: What the Creator Now Recommends

For 30 years, retirees have trusted the 4% rule to make their savings last. But William Bengen, the financial planner who invented it, later said …

12 min
Retirement Calculator: Inputs That Determine Success

Retirement Calculator: Inputs That Determine Success

Before you can stress-test your retirement plan against 100+ years of market history, you need to understand what you're actually testing. This guide breaks down …

11 min