What it says

How this squares with the guide

How it is computed

• A window is a run of consecutive calendar years, say 1929 through 1938. Its annualized return is the compound rate that turns the product of the yearly total returns into the same ending value: (Π(1 + r))^1/n − 1. Every possible window is counted, so a 10-year holding period has 89 windows from 1928–1937 to 2016–2025.
• The funnel draws, for each holding period, the worst and best window (the whisker), the middle half of windows (the box, 25th to 75th percentile, interpolated) and the median (the line across the box).
• After inflation deflates each year by that year's December-to-December CPI change: (1 + r) / (1 + inflation) − 1, the same way Damodaran computes his real returns. It is the default because the lesson's point is that inflation, not volatility, is the long-run risk, and nominal figures hide it: before inflation, Treasuries lost money in 10-year windows here; after inflation, they lost in .
• “Stocks beat bonds” compares the two annualized returns for the same window. Deflating both by the same inflation never changes which one is ahead, so that row reads the same in both modes; the “lost” rows do change.
• Returns are pre-tax and pre-fee, reinvest every dividend and coupon, and assume no money goes in or out during the window.