There is also what is called hyper DCA, this method is a kind of pattern that one can buy bitcoin anytime and not with a certain amount of money, just like the way MicroStrategy buys his bitcoin. For you to know that he is DCAing is when you add all the bitcoin that he has bought together, and how many years he has used to buy them. This will give you the average price by month or annually.
DCA is one of the basic form of investment if you want to secure for the long term, but in my opinion its ideal if the person who would like to trade have a basic understanding with the market like charts, and indicators this serve to them an advantage for example the market possible makes a dip of the price so its a good opportunity to them to have a position to buy so if the market makes another dump they makes a gain, and if the market backs to the bottom its okay because until it didn't hit their buy position at all.