Assuming you plan to invest for 12 months by dollar cost averaging, and you keep buying 200$ worth of bitcoin every week or month, do you know that there will be times where the market will go up rather than down? DCAing at such times are increasing your risks.
If after you did a DCA round, price goes up, it is good because you can sell it for profit.
There is a saying that, stay away from the green candles, do not chase them.
I know you want to find better or best entries for your DCA but by being obsessive with finding good entries, you are becoming a speculator, trader, not an investor with DCA strategy.
When you try to do this, you will find bottoms by that you will miss bottoms.
Monthly investment is the best frequency to some people, they advice to never delay any investment, are you one of those people? Regarding of the price action of that month?
You can DCA monthly or quarterly if you don't have big capital to do weekly DCA. Because if you use too small capitap for DCA, you will pay higher rate for withdrawal fee compares to total capital you buy at that time.
Buying on an exchange and leave your bitcoin there, wait for two or three months for one withdrawal is terrible practice.
Reminder: Do not keep your money in online account.