I prefer to do DCA when the market is in a downtrend. I tried to buy every dip possible and kept doing this till the coin flipped. If you want to keep my profit booking strategy, then it totally depends on the bitcoin market. As soon as i got confident that bitcoin is at its peak for this bull season it was time to start booking in altcoin too. This is the time when most of the altcoins start pumping and start making new ATH.
DCA is always the best way to invest in cryptocurren and the market correction season especially when there's a lot of panic in the market is the time to invest in Bitcoin and the altcoin that will always follow the BTC market trend when it halving season.
That's my own strategy of investment. However, investing in altcoin market when the some altcoins start to pump is good but it's best when there's correction.