October 4, 2026 · BriMindInvest Research Team · 12 min read
Every week on r/Bogleheads, r/investing, and r/portfolios, someone asks: “Is this allocation good?” The answers are always confident, rarely data-backed. So we took five of Reddit's most recommended portfolio allocations, ran 2,000 Monte Carlo simulations on each, and let the numbers decide which ones actually survive 10, 20, and 30 years of market chaos.
These are not theoretical constructs. Each portfolio is a real allocation that gets recommended multiple times per week across investing subreddits. We used historically calibrated return distributions for each asset class (mean, standard deviation, and cross-asset correlations based on 1972-2025 data) and ran 2,000 independent simulation paths per portfolio.
Before the results, here is exactly what we did so you can evaluate the assumptions:
Monte Carlo simulations are not predictions. They are stress tests. Future returns could be structurally different from the past (lower bond yields, higher equity valuations, new asset correlations during crises). The value is not the specific numbers but the relative ranking and the shape of the distribution tails. Treat these as “if history rhymes, here is what to expect” rather than guarantees.
This chart shows the median (50th percentile) outcome for each portfolio over 30 years. This is your “most likely” scenario — half the simulations did better, half did worse.
The aggressive growth portfolio (red) pulls ahead dramatically in the median case — $455,600 on a $10,000 investment. But this chart only tells half the story. It is the equivalent of saying “the average lottery winner is a millionaire.” You need to see the downside.
In the worst 5% of simulations, the aggressive portfolio (red) is underwater for the first decade and barely recovers by year 20. The Boglehead three-fund (green) never dips below the starting value after year 7. The All-Weather (yellow) stays above water the entire time. This is why risk-adjusted returns matter more than raw returns.
Starting with $10,000 invested today. All values represent the ending portfolio value across 2,000 simulated paths.
| Portfolio | Median Value | Worst 5% | Best 5% | Sharpe | Max Drawdown |
|---|---|---|---|---|---|
| Three-Fund Boglehead | $24,000 | $15,800 | $38,200 | 0.72 | -28% |
| 100% VTI | $26,800 | $13,400 | $46,500 | 0.65 | -38% |
| VXUS Tilt | $21,900 | $14,200 | $34,100 | 0.61 | -32% |
| All-Weather | $17,500 | $14,800 | $21,600 | 0.78 | -14% |
| Aggressive Growth | $35,700 | $8,900 | $89,200 | 0.52 | -56% |
At the 10-year mark, the All-Weather portfolio has the best Sharpe ratio (0.78) and the shallowest drawdown (-14%). The Aggressive Growth portfolio has the highest median ($35,700) but also the worst floor ($8,900 at the 5th percentile — you could lose 11% of your money over a decade). For money you might need in 10 years, the Boglehead or All-Weather strategies are significantly safer bets.
Same starting $10,000 investment. Twenty years of compounding, annual rebalancing, with expense ratios deducted.
| Portfolio | Median Value | Worst 5% | Best 5% | Sharpe | Max Drawdown |
|---|---|---|---|---|---|
| Three-Fund Boglehead | $57,700 | $29,300 | $118,000 | 0.74 | -32% |
| 100% VTI | $72,200 | $24,100 | $178,000 | 0.68 | -42% |
| VXUS Tilt | $47,900 | $26,200 | $96,800 | 0.62 | -36% |
| All-Weather | $30,200 | $23,200 | $41,800 | 0.81 | -16% |
| Aggressive Growth | $127,500 | $15,200 | $512,000 | 0.55 | -62% |
At 20 years, the gap between portfolios widens dramatically. The aggressive portfolio's best-case ($512,000) is almost 12x the All-Weather best-case ($41,800) — but the aggressive worst-case ($15,200) is worse than most other portfolios' worst cases. The Boglehead's Sharpe ratio (0.74) is now within striking distance of the All-Weather (0.81), because 20 years of equity compounding begins to dominate bond stability.
The full career horizon. If you are in your 20s or 30s, this is your investing lifetime.
| Portfolio | Median Value | Worst 5% | Best 5% | Sharpe | Max Drawdown |
|---|---|---|---|---|---|
| Three-Fund Boglehead | $138,900 | $62,400 | $342,000 | 0.76 | -34% |
| 100% VTI | $194,400 | $48,900 | $586,000 | 0.70 | -45% |
| VXUS Tilt | $105,100 | $53,500 | $248,000 | 0.64 | -38% |
| All-Weather | $52,200 | $37,100 | $78,600 | 0.83 | -18% |
| Aggressive Growth | $455,600 | $28,800 | $2,840,000 | 0.57 | -68% |
The aggressive growth portfolio leads in absolute median value ($455,600), but has a variance range from $28,800 to $2.84M. The Boglehead sits at $138,900 median with a much tighter band of $62,400 to $342,000. Which one lets you sleep at night?
The answer depends entirely on what you are optimizing for. Here is who wins each category at the 30-year horizon:
If you rank by risk-adjusted returns (Sharpe ratio), the All-Weather portfolio wins at every time horizon. If you rank by median terminal value, the Aggressive Growth portfolio wins. But here is the part Reddit threads never mention: most people do not hold for 30 years without touching their portfolio. They panic-sell during drawdowns, they rebalance emotionally, they need the money for a house. The portfolio you can actually stick with during a 40% drawdown is better than the portfolio with the highest theoretical return that you sell at the bottom.
For most investors, the Three-Fund Boglehead portfolio hits the sweet spot: strong median returns, a solid worst-case floor, manageable drawdowns, and dead-simple execution. It wins zero individual categories but finishes top-3 in every single one. That consistency is the actual edge.
The data confirms it. Low-cost, diversified, buy-and-hold portfolios produce excellent risk-adjusted outcomes over long horizons. The three-fund portfolio is not exciting, but it finishes in the top 2 for worst-case outcomes at every time horizon we tested. There is a reason Bogle has a following.
Over 30 years, 100% VTI beats the three-fund portfolio in median terminal value ($194,400 vs $138,900). The simplicity premium is real — no rebalancing decisions, no allocation debates, no drift. The cost is a deeper max drawdown (-45% vs -34%) and a worse floor ($48,900 vs $62,400). If you can genuinely stomach a 45% drawdown without selling, 100% VTI is a defensible choice.
The aggressive growth portfolio has the highest ceiling and the lowest floor. In the worst 5% of simulations, you could invest $10,000 for 30 years and end up with $28,800 — a 2.8% annualized return that barely beats inflation. Meanwhile, the Boglehead's worst case ($62,400) is a 6.3% annualized return. Concentration risk is real, and it compounds over decades.
This one is nuanced. The VXUS Tilt portfolio does lag in raw returns ($105,100 vs $138,900 for the Boglehead). But it has a better worst-case floor than 100% VTI at every time horizon. The decades when US equities underperform international equities (1970s, 2000s) are exactly when you need that diversification most. The problem with backtesting is that US outperformance since 2010 makes VXUS look permanently inferior — that is recency bias, not analysis.
Reddit portfolio advice suffers from massive survivorship bias. The people posting their returns are the ones who did well. Nobody makes a post titled “I went 100% QQQ and lost 40% in 2022.” Monte Carlo simulations do not have this bias — they show every outcome, including the ones that never get posted.
These five portfolios are starting points, not prescriptions. Your ideal allocation depends on your time horizon, risk tolerance, income stability, and whether you actually hold during drawdowns (be honest with yourself). Use BriMindInvest's portfolio analyzer to build a custom allocation and compare it against these benchmarks.
Enter your tickers and weights, and the tool calculates correlation matrices, historical drawdowns, sector concentration, and fee drag — the same analysis we used for this study, applied to your specific portfolio.
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