Étude de cas
Building a $10K starter portfolio for a 25-year-old
Maya is 25, earns a stable salary, and just finished an emergency fund. She has $10,000 to invest with a 30+ year horizon. Walk through the path: her risk score lands her in 'Aggressive' (70% stocks / 15% bonds / 10% alternatives / 5% crypto). Run the Two-Asset lab on a stock/bond core to see how diversification cuts σ from ~18% to ~13%. Plot the Efficient Frontier on SPY+AGG+GLD and pick the tangency portfolio for the maximum Sharpe. Apply CAPM with β=1.0 and a 6% premium → a 10% expected return. Over 30 years that compounds the $10K to roughly $175K (real terms, before fees) — the textbook power of long-horizon compounding combined with mean-variance optimization.