By the most logical thinking:
There's strong evidence that the late 2017 spike in Bitcoin value was due to manipulation via Tether.
IF that is so, then that entire episode actually means nothing, and...
Bitcoin etc values will decay back to their historical levels prior to pump & dump.
This will be slow because interim buyers won't want to take the losses.
Look at BC charts for the past 6 months. It's very easy to imagine the average value continuing to decay down to $400 in 12-18 months. And that's what makes sense - at least, more sense than anything else.
A few brilliant traders will make money getting in and out during the decline, but all the other players here are just rearranging deck chairs on the Titanic. The only "charting" you need is the big picture here:
https://imgur.com/a/QTYOQyLUnfortunately, there seems to be no reliable way to buy a put on BC for that time-frame, or I would.
Cryptocurrency and blockchain technology are here to stay and thats the future, there are many coins created and will be created but the ones which are of value to the people ,the ones which serve some particular purpose are used and will continue to be used and thats BITCOIN.