PAC backtest: 10 ETFs, 6 portfolios
Pick an ETF or a portfolio mix, set a monthly contribution and a horizon, and see one calibrated walk through the math. Includes the time-in-market experiment.
PAC stands for Piano di Accumulo Capitale — a regular, automated monthly investment. This tool walks one calibrated path through the math: pick an ETF or a portfolio mix, set a monthly amount + horizon, and watch the gap between what you contributed and what the portfolio became.
For probability-of-outcome questions ("what's the chance I beat my target?"), use the Monte Carlo simulator. For pure deterministic compound-interest math, use the compound interest calculator.
Time in market vs timing the market
Toggle a button below to remove the N highest months. Time-in-market discipline matters far more than people think — missing the best 20 months in a 20-year run typically halves the ending value.
Methodology: monthly returns are generated from each asset's documented annualized total return and volatility (lognormal walk, fixed seed). This is not a literal replay of historical month-by-month moves; it is a calibrated synthesis with the right distributional moments. Use the Monte Carlo tool for probability-of-outcome questions; use this tool to feel the shape of one realistic accumulation path.
What this tool does, in one paragraph
For each ETF / portfolio you pick, the tool generates a sequence of monthly returns calibrated to that asset's documented annualized total return and volatility (sourced from MSCI factsheets, S&P, Bloomberg index pages, Borsa Italiana, LBMA, ECB). It then walks the PAC: starting with your lump sum, contributing your monthly amount, compounding through each generated return minus the ETF's TER drag. The chart shows the contributed total (dashed) versus the portfolio value (filled); the gap between the two lines is the part you didn't deposit. That's the entire game.
The "miss the best N months" buttons toggle a recompute that drops the top N monthly returns and replaces them with zero. The dashed grey line on the chart, when active, is what your run looked like before the drop. Missing the 10 best months in a 20-year run typically wipes out roughly half the ending value — which is the lesson that time in the market beats timing the market, made tactile.
The 10 ETFs supported
All UCITS, EUR-domiciled, accumulating share classes where available:
- VWCE — Vanguard FTSE All-World (acc). The one-fund answer: 4,000+ stocks, developed + emerging.
- SWDA — iShares Core MSCI World (acc). Developed-market only, 1,500+ stocks.
- CSPX — iShares Core S&P 500 (acc). Just the big US names; lowest TER (0.07%) of any major index.
- EIMI — iShares Core MSCI EM IMI (acc). Full IMI coverage including small caps, ~3,000 emerging-market stocks.
- WSML — iShares MSCI World Small Cap. The small-cap-factor counterpart to SWDA.
- MEUD — Amundi STOXX Europe 600 (acc). Pan-European exposure.
- ITPS — iShares FTSE MIB (acc). Italian equity benchmark, the home-country tilt.
- AGGH — iShares Global Aggregate Bond EUR Hedged. The default "bonds" sleeve for European investors.
- IBGL — iShares Core EUR Government Bond. European sovereign-debt only.
- SGLD — Invesco Physical Gold ETC. Real gold, vaulted; 0.12% TER.
The 6 preset portfolios
- 100% Global Equity — full VWCE. Highest expected return, longest expected drawdowns.
- 60/40 Classic — 60% global stocks, 40% global bonds. The textbook balanced portfolio.
- 80/20 Aggressive — for longer horizons or higher risk tolerance.
- 3-fund Bogleheads — 50% developed, 25% emerging, 25% bonds. Diversified at minimal complexity.
- Permanent Portfolio — Harry Browne's 25/25/25/25 across stocks, long bonds, gold, and cash. Famously smooth, modest expected return.
- All-Weather (lite) — Ray Dalio-inspired bond-heavy mix. Designed to perform across regimes.