Concept
The 4% Rule
2 books in the library reach for this idea - each in its own way. When independent authors converge on one concept, it usually deserves attention.
Set for Life
How this book uses it: You need 25x annual expenses invested to retire safely. Calculate your FI number: Annual Expenses × 25.
The Simple Path to Wealth
How this book uses it: You can withdraw 4% of your portfolio annually with high confidence it will last 30+ years. $1M invested = $40K/year.