Return Data Source
Fama/French 3-Factor Dataset (Ken French, Dartmouth): Monthly total-market returns, July 1926 – April 2026. Total return = Mkt-RF + RF, where Mkt-RF is the value-weighted return of all CRSP firms on NYSE, AMEX & NASDAQ in excess of the 1-month T-bill rate, and RF is that T-bill rate. Underlying data: CRSP. Download dataset (Dartmouth) ↗
U.S. Bureau of Labor Statistics (CPI-U): Monthly CPI-U all-items index used for inflation adjustment and suggested inflation rates. Pre-1947 figures from historical BLS series. BLS CPI data ↗
Note on index: This tool uses the US Total Market (all publicly traded US equities, value-weighted), not the S&P 500 specifically. In most years the two track very closely; meaningful differences arise primarily when small-cap stocks diverge sharply from large-cap performance.
What This Tool Shows
For each selected 30-year period, the 360 underlying monthly returns are grouped into 30 annual blocks. Good Start sorts blocks best-to-worst by annual return; Bad Start sorts worst-to-best. Historical Order preserves chronological sequence. Flat Average applies the period CAGR uniformly as a constant monthly rate. Portfolio simulation runs 360 monthly steps with inflation-adjusted monthly withdrawals.
Simulation Mechanics
Monthly withdrawal is entered directly and inflation-adjusted each month using (1 + annual rate)1/12 − 1. Portfolio is floored at $0. Depletion is recorded the first month a withdrawal reduces the balance to $0 or below; the balance remains $0 for all subsequent months.
Period Selection
1929–1958: Great Crash, Depression, WWII, post-war recovery. 1950–1979: Post-war boom into oil crises and stagflation. 1966–1995: Historically the most challenging period for retirees, combining Vietnam-era losses, double-digit inflation, and the 1982 bull market recovery. 1975–2004: Bull market start, dot-com bust at close. 1982–2011: Golden age of equities, then dot-com and 2008 crises. 1996–2025: The most recent 30-year window, covering three major drawdowns and most directly relevant to clients retiring today.
Why Sorted Sequences Are Used
Sorting the same returns two ways isolates sequence risk from every other variable. The gap between Good Start and Bad Start is attributable entirely to the order of returns; nothing else changes.
Illustrative Survival Rate
10,000 Monte Carlo trials. Each trial randomly shuffles the 30 annual blocks (Fisher-Yates), then runs a full 360-step monthly simulation. Reported as the share of trials in which the portfolio reaches month 360 above $0. The simulation runs independently on each page load or input change, so the figure may vary by a small amount between updates; differences of 1–2 percentage points are normal.
Averages & Statistics
All averages shown are geometric (CAGR). Standard deviation uses the arithmetic mean of annual returns as is conventional for dispersion measures.
Disclosures
Donohue Wealth Management is a DBA of McAdam LLC, an SEC registered investment adviser. For educational and illustrative purposes only. Does not constitute investment advice. Historical returns do not guarantee future results. No fees, taxes, or transaction costs are reflected. Results are hypothetical. All scenarios represent a 100% equity portfolio.