Some of you noticed this type of technique and most of that people who knows have the most calm and smart way of trading. As you can see on the diagram above, you will notice that bitcoin for example has a cycle which happens all the time like what happened last 2017 moon, 2018 drop and possible another 2019 moon. This technique are usually profitable for hodlers and traders.
This is how it works. If the value of the bitcoin for example has reached its peak, don't buy any of it. Wait until it goes down fully into its peak. After you noticed that it is already consecutively increase, its now time to buy. If you are not sure about whether its now time to buy or not, its normal. Remember that you always have a chance for another cycle.
Now, If you want to play safe, if the value decreases consecutively and become stagnant for a while, buy some. If it increases then sell it at once. Trading really requires time and decision making. If you know how to do it well depending on your technique then it will work well.
To summarize it all, Bitcoin always has its phases in a cycle so if you feel that you didn't ride on a rocket going to moon, don't feel hopeless because there's always another cycle to start. Its just a matter of time and patience.