I'm nominally 100% equities. I invest for total return. I raise cash when the portfolio value is above retirement projections, which would always be in a market hitting new highs. I do not reinvest fund distributions. I sell equities to meet expenses if I don't have cash sitting around, in a way that rebalances the portfolio equities. If I have excess cash and the market drops more than 20% I will begin buying equities, which would always be when the market is hitting new lows, adding more in steps if the market continues down.
I started retirement in 2007 when the economy was looking shaky so I had about 3 years of cash to start just in case. That came in handy. I was able to buy as the market declined and have hit new portfolio highs since then. If the market had gone up instead I would have used all the cash for expenses before selling any more equities, so I wouldn't be carrying lots of cash for a long time period.