who says bitcoin will go down to $ 900, who says it will go up to $ 100,000.
a lot of people are saying random shit on the internet but they are not "predicting" anything they are bullshiting some guess in both cases actually.
there is no reason for bitcoin to go that low ever and there is no reason for it to rise that big now. there is a solid rise going on and we are headed to much higher prices, that is all you can say.
In this branch, not only do I want to know by what signals and technical analysis you determine how much and when btc and other altcoins will cost?
well TA doesn't work at all when it comes to altcoins. you can try using it and get lucky to get a couple of speculations right but generally it doesn't work for them at all.