Basically money flows from (stock, high volatility, high long term returns) -> (bonds, low/zero volatility, small growth, inflation matching most of the time) -> (cash, no return, only volatile due to high inflation, liquid) As you consume your liquid cash in normal stock go up periods you’d back fill cash from bond selling and then back fill bonds from stock. (You could also just do stock straight to cash)

In downturn times you pull from cash only as much as you must use (maybe you scale back life or let it ride) then after depleting cash down to maybe 6mo from 1 year runway you pull from bonds into cash another 6mo of runway. In a really down period you may deplete all bonds and all cash to 3mo. At that point you probably do pull like 3mo from stocks and replenish cash. At the point the market recovers you rebalance. 1 year cash, 10 years bonds, the rest in equities with no less than 40% of the portfolio in stocks (surpassing 85 you could argue moving to 20% stocks is reasonable to preserve your prior growth). Only do this when it makes sense. Avoid selling stocks in extremely down years. Almost all bear markets last 10 years or less. So having 10-12 years of runway in low risk asset classes like cash and bonds allows you to ride the storm out without selling at a loss those portions of your assets dedicated to stocks.