this one thing could be rougly determined from technical analysis honestly I doubt someone could determine this without any technical analysis, though DCA method is one way to get profit and find better entry but it still requires investment overtime which easily means we might also get some bad entries, but with technical analysis i guess we could get rougly estimation of when the market gonna bottoms out.
the most important thing is we have to choose the right cryptocurrency before doing DCA, because when doing DCA in a bad cryptocurrency or shitcoin, then of course it's just a waste of our money, therefore I recommend investing and DCA in cryptocurrency that are in the top 10 on coinmarketcap, because it's safer and for sure the price will increase, so it can give us a big profits in the future.
It is the very first step to choose the correct cryptocurrency that you will be investing in whether you are going to do DCA or simply buy all-in, though it is not recommended to buy all-in even if you are buying a shit coin because there is always the chance of it either going up or down, so if a cryptocurrency manages to up after you buy all-in, you will be in more profit, if it goes down from that point, you will regret your decision of buying all at once.
And, people usually do DCA with coins that have a significantly high value like Bitcoin or Ethereum and some other cryptocurrencies, and DCA is done when you are planning to hold on to the assets for the long term, if you are buying for the short-term, you should go for buying with an amount that you are willing to invest.
