Core + Alternatives — Portfolio Simulator
The four core building blocks, plus the popular alternatives: real estate, gold, and Bitcoin. A single "you'll have $X" number is a guess: real markets are random, so this runs 2,000 market paths and shows the range. Everything runs in your browser; nothing is sent anywhere.
Your plan
Allocation 100%
Overweight your own market: pick a country and give it a %, then trim the others so the total stays 100%. Uses that region's ~30-year USD return and volatility.
Set any asset to 0. Your allocation must total 100% before you run.
Saved only in this browser (no account, nothing uploaded). Load one to restore your allocation and plan.
Saved plans
10th – 90th percentile
the range 8 in 10 simulations landed in
Median: half did better, half worse (a typical outcome)
High: top 10% (a strong market) · Low: bottom 10% (a weak market)
What each asset means
US stocks: The entire US stock market — every American public company, from Apple down to the smallest. The core engine of most portfolios.
Developed ex-US: Large companies in developed countries outside the US — Europe, Japan, Australia, Canada. Diversifies away from a single country.
Emerging markets: Companies in faster-growing, less-established economies — China, India, Brazil, Taiwan and more. Bigger swings than developed markets.
Bonds: US investment-grade bonds — loans to the government and solid companies that pay interest. Lower return, but far steadier than stocks.
Real estate (REITs): Real Estate Investment Trusts — companies that own income property (apartments, warehouses, malls). Real-estate exposure you can buy like a stock.
Gold: Physical gold. It pays no income, but often holds its value when stocks or the dollar are struggling.
Crypto (Bitcoin): Bitcoin, as the representative crypto asset. Very large swings in both directions. Its expected return here is a long-term estimate, set well below its short early history.
The data behind it, and how the simulation works
Each simulated month, your portfolio earns a random return based on its blended expected return and volatility. We do that 2,000 times and report the range.
1. Blend your mix into one return + volatility (assuming annual rebalancing): μₚ = Σ wᵢ·μᵢ, σₚ = √(ΣΣ wᵢwⱼσᵢσⱼρᵢⱼ).
2. Annual → monthly: m = (1+μₚ)^(1/12) − 1, s = σₚ/√12.
3. Each month, draw a random return from a lognormal calibrated to (m, s).
4. Grow and add contributions: Bₜ₊₁ = (Bₜ + contribution) × (1 + rₜ), until the "keep investing for" cutoff.
5. Repeat 2,000×; sort the ending values; report the 10th / 50th / 90th percentiles. "Today's dollars" divides by (1.025)^years.
The numbers used (nominal annual return + volatility, ~30-yr history where available):
| Asset | Proxy | Return | Volatility |
|---|---|---|---|
| US stocks | CRSP US Total Market (VTI) | 10.5% | 15.7% |
| Developed ex-US | MSCI EAFE (EFA) | 5.9% | 16.4% |
| Emerging markets | MSCI EM (EEM) | 6.5% | 22.2% |
| Bonds | Bloomberg US Aggregate (BND) | 4.0% | 4.2% |
| Real estate (REITs) | FTSE NAREIT (VNQ) | 8.0% | 18.0% |
| Gold | Spot gold (GLD) | 5.0% | 15.0% |
| Crypto (Bitcoin) | Bitcoin (BTC) | 15.0% | 65.0% |
- Method: each figure is the long-run average from roughly 30 years of history (about 1996–2026 for US, developed, emerging, bonds, REITs and gold; Bitcoin uses ~10 years, deliberately moderated well below its short history).
- Sources: index total-return series (VTI, EFA, EEM, BND, VNQ), spot gold and Bitcoin via lazyportfolioetf.com, cross-checked against S&P 500, MSCI and Bloomberg index fact sheets.
- Small/large and growth/value sub-classes are estimated from the matching Russell and MSCI indices; correlations are approximate long-run values.
- Home-country tilt: ~30-year USD total returns (unhedged, so they include currency moves): Canada 8.6% / 20.1%, UK 6.5% / 16.6%, Australia 7.6% / 21.7%, Europe 7.3% / 18.0% (via lazyportfolioetf.com).
- These are historical assumptions, not forecasts.
Illustrative, not financial advice. See the disclaimer.