The only data we have when it comes to volatile asset market like bitcoin is historical data. Everyone is depending on historical data to make analysis and give their speculation of the future price of bitcoin. Nobody knows the future to know precisely what bitcoin price would be, whether you're trading or investing, use funds that doesn't scare you to use and bury that greed and impatient so you don't hit a rock bottom before you practically start.
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This is true about all technical analysis, even though with the 4 year cycle bitcoin somewhat relies on the halving being part of fundamental analysis.
And if there's a time in the future, when bitcoin won't break the next ATH within 4 year cycle, we shall be in even more uncharted waters. At such time, i wouldn't trust ANY predictions.