Emergency Fund

Splitting retirement assets into three "buckets": short-term cash (1–2 years), medium-term bonds (3–10 years), and long-term stocks (10+). Refill each bucket from the next one in good market years.

(Income − Expenses) ÷ Income. The single most important variable for years-to-FIRE. A 50% savings rate reaches FIRE in ~17 years; a 20% rate takes ~37.

The risk of bad market returns in the first few years of retirement, which can permanently damage your portfolio even if average returns are fine. Mitigated with bond tents and cash buffers.

Gradually increasing your bond allocation in the years leading up to retirement, then reducing it again after — a "tent" shape — to buffer against sequence risk.