How should I set my asset allocation based on my goal and time horizon?

Match the riskiness of your allocation to when you'll spend the money. For goals 15+ years out (retirement in your 30s/40s), a heavy stock tilt — often 80–100% equities — lets you ride out downturns and capture growth. For goals 5–10 years away, dial stocks back toward 50–70% and add bonds to cushion volatility. Money you need within 3 years generally shouldn't be in stocks at all; keep it in cash, T-bills, or a high-yield savings account. The longer your horizon, the more short-term swings stop mattering, because you have years to recover before withdrawing. Separate each goal mentally and let its timeline drive the mix rather than using one blanket allocation. A good starting point: wealthserene.com/tools/portfolio-builder to translate a goal and timeline into a target stock/bond split.