What asset allocation makes sense for a retirement that could last 40 or 50 years?

For a multi-decade retirement, you generally need more stocks than a traditional retiree, because over 40–50 years inflation is the bigger threat than short-term volatility, and an all-bond portfolio simply can't keep up. A common FIRE range is roughly 70–80% diversified stock index funds and 20–30% bonds and cash, sometimes called the growth-tilted glidepath. The bond and cash sleeve isn't for returns — it's a buffer so you don't have to sell stocks during a crash early on, directly reducing sequence-of-returns risk. Keep it broadly diversified and low-cost; concentrated bets add risk without reliably adding return. Your exact split depends on how flexible your spending is: the more you can cut in down years, the more stocks you can hold. Build and stress-test an allocation at wealthserene.com/tools/portfolio-builder.