Simulate

The Monte Carlo simulation plays out your plan a thousand times with randomly varying market returns and inflation, then reports how often your money lasted. It's the difference between one forecast and a stress test.

Running a simulation

Press "Start Simulation". The chart fills with a fan of possible net-worth paths — a median line with shaded probability bands around it — and the Success Ratedial shows the share of simulated futures where your money didn't run out before your life expectancy. Teal is comfortable (80%+), yellow means borderline, red means the plan needs work.

Screenshot coming soon: A completed Monte Carlo run: outcome bands, median line, and the success dial

Reading the result

The success rate is a probability across simulated futures, not a guarantee — 90% means 1-in-10 simulated futures still fell short.
The bands widening over time isn't noise: uncertainty compounds over decades, which is exactly what the simulation is showing you.
The "Current Financial Summary" below the chart shows the inputs the run started from: accounts, assets, debts, income, and expenses as of today.

Good to know

Results are cached — if you change your data elsewhere, the dial still shows the old run until you press "Re-run Simulation". Check the "Last run" date.
You need at least one person plus one account, asset, or income before a simulation can run.
The assumptions behind the randomness — inflation volatility, per-asset-class returns, correlations — live on the Settings page.

Still stuck? Contact support — we read every message.