The best time for buying is at low price and I think if you sell your coins with profit then you should not regret after Fluctuations in coin price because you have already taken your profit so ready to make another step instead of regret about past.
If you are in doubt about other coin then just buy bitcoin now and don't sell until you achieved your target. This time is not suitable for selling but if someone is in huge profit and he cannot hold longer then selling should be preferred. Understand the market and accept your profit but I think if someone is selling their bitcoin without waiting more so he will miss the opportunity of having huge profit in Bull season.
I think it is right that if you buy at a low price and later sell when the price increases, then the profit will remain. There are many who do not want to buy when the price decreases but if we pay attention, we will see that when the price of Bitcoin decreases, it increases again, in which case you can invest in Bitcoin and in the long run there will be a huge profit opportunity. The right time for you to sell is when you get the price you want. If you get the price twice as much as you expected now, then sell.
Yes in addition and to be specific on your last statement, the reason why we are investing in Bitcoin is not just after getting to our set target we sell rather we are so Investing to have this asset in our portfolio for long that is continuously and it is advised to sell little cent and be accumulating back even though the rate of accumulation is not the same initially. Remember even in other investment, the reason is not just to sell and make profit but the reason is also to have an investment that will stay, investment that will last and to be able to get to this stage and be doing this, you have to be deligent and consistent.
Buying bitcoin when the price drops, indeed it is an opportunity that should not be wasted. Because basically it could be that bitcoin does not touch that price again and continues to rise, so the point is that when there is momentum the price of bitcoin truth drops, then if we have discretionary funds, then immediately buy. But even so, don't misunderstand this. Because if for example we deliberately wait for the price of bitcoin to drop to make a purchase, it is clear that the action is not good. So the price drops that I personally mean, when accidentally not on purpose. Because if you deliberately wait for the price of bitcoin to drop, I think it will actually make us lose momentum. So basically we have to do DCA as much as possible against bitcoin. So don't focus too much on the price drop. But if the price of bitcoin drops slightly, when we do DCA maybe the nominal is increased if any. But if not, I think doing DCA as usual is more than enough.