TL;DR
The heatmap colors each historical cohort green (survived comfortably), amber (survived with low buffer), or red (failed). Clusters of red identify the specific regimes your plan can't handle.
In short
If you see red clustered around 1929, 1966, and 2000, that's the classic sequence-risk pattern. If red is scattered randomly across decades, it's more likely a methodology artifact. Reading the heatmap teaches you to think in terms of regime risk, not single-point probabilities.
We're working on a full deep-dive for this article — including historical data, charts, and worked examples. In the meantime, you can run a free simulation to explore the underlying numbers yourself.
Frequently asked questions
- What does an amber result mean?
- The plan survived but with a thin terminal buffer — typically the portfolio dropped below 25% of starting value at some point. Survival was technical, not comfortable.
- Should I be worried if my plan fails one or two cohorts?
- Depends which ones. Failing 1929 and 1966 means your plan can't handle the worst historical scenarios. Failing 1969 alone is less alarming because the post-1969 stretch was anomalously bad even by 1929/1966 standards.
Stress-test your own FIRE plan
FIRE Wealth OS runs your savings rate and expenses against every historical market starting point since 1871. Free to use, no card required.