Here’s a quick test to see if you act your age: Explain the “4% Rule” in investing.

If you are a Baby Boomer or Generation X member, you have probably heard of the gold standard for retirement planning. Specifically, that if you withdraw 4% of your initial portfolio value and adjust for inflation each year, your money should last 30 years.

For decades, this was a theory built on a volatile 60/40 mix of stocks and bonds. But as I write this in late March 2026, the bond market is offering a rare gift that turns this rule from a statistical hope into a mathematical near-certainty, at least on a pre-tax basis.

Here’s the yield curve and rate tables for Treasuries as of Monday’s market close. I see a lot more…