Nobody can understand the market accurately and predict how it will behave. However, one can make informed trading decisions if they have understanding of technical and fundamental analysis. Analysis can help give you a better understanding; however, there is no guarantee.
FA and TA are only 50% correct, because so much of speculation happening in an unregulated market, you have to know how you can use it to your advantage and not how to predict a movement.
One thing I understand is that you have to be ready with both BTC and Fiat at all times if you want to execute some profiting trades. When the market is dropping use the Fiat to buy and when the market is rising use the BTC to sell. Now the only thing that you decide on your own is the point of selling or buying. This will depend on support and resistance levels.
If you follow what I said above, you will be able to make gross profits over large margins but it will take time. Patience is the key here. Those who bought at 19k USD at the first bitcoin ATH above 19k, were angry that the market crashed after that and tried to panic sell. Had they been holding all these years they would have got 2x gains on the price today.