It has become really hard to predict BTC price these days because of the large volatility.
Even if we think of a certain price then comes a sudden pump at the end of the week and we lose our bets.
But I guess that's the spirit of betting. I guess $80k - $100k is a good price range for this bet.
The most popular range for this bet is between 70-80K while the second popular is the range between 80 - 100K. I think you can even place the bet on the range between 65-70K and still fancy your chances to win. The bitcoin market is too much volatile that the last minute bitcoin pump or dump can make you lose or win these bitcoin predictions bets.
Another thing to note is that Bitcoin is very volatile on the last day of the month because of the monthly closing and we usually see big moves near or on those dates. So my conclusion is that bitcoin price prediction is just luck based as it is impossible to determine the price of bitcoin beforehand.
