The backtest runs automatically once your portfolio has loaded, so results are usually waiting when you open the tab. Changing an input marks the saved run stale and offers a re-run.
Step by step
- Open the Backtesting tab. If a saved run exists it loads immediately, with no recalculation.
- Check the survival rate. The share of historical start years in which the plan funded the whole horizon.
- Compare allocations. Your current mix, 100% stocks, 60/40 and 30/70 are run against identical start years and withdrawals, so differences come from the allocation rather than the sample.
- Open a single world. Drill into any start year to see its full path, deepest drawdown and annual returns. The 1966 and 1929 starts are the instructive ones.
Remember that historical windows overlap heavily — a 30-year test starting in 1929 and one starting in 1930 share 29 years — so the effective sample is much smaller than the number of windows suggests. Treat the survival rate as a robustness check, not a probability.