Should I hold a cash-and-bond 'buffer' to avoid selling stocks in a down market after I retire early?

Yes, a buffer is one of the most practical defenses against sequence-of-returns risk. The idea is to keep one to three years of essential expenses in cash and short-term bonds so that when stocks fall, you spend from the safe bucket instead of selling equities at a loss. This gives your stock holdings time to recover before you have to touch them. The trade-off is cash drag: money sitting in cash earns less over decades, so an oversized buffer can lower your long-run returns and even raise your FIRE number. Most early retirees settle on roughly 1-2 years of spending in cash plus a bond allocation, refilling the cash after good market years. Pair this with flexible spending for the strongest protection in your first decade of retirement.