One of the problems, with bitcoin , is that we miss long term bitcoin data. There is not a single source from which to gather the value of bitcoin in any moment from it's inception. Or at least from when it was first exchanged into exchanges. If you look at coinmarketcap the data go back to the 28 apr 2013. But mtgox started in July 2010. If you go to yahoo, you will be able to gather data, but once you start working with this data you soon find out how poor is it. Basically it follows mtgox data while mtgox was alive, and then switched to some other exchange. But this means that we see a sudden jump in data which makes any indicator go wild. Basically it's really difficult to gather long term data on bitcoin . Also consider that mtgox did not just "go away" when it stopped trading. But in the database here it is still present with the fixed exchange rate of when it stopped.
So I tried to create the data we need. How? By taking three exchanges, and taking the median between them. The three exchanges I took were MTGOX: , BITFINEX: and KRAKEN: XBTUSD . We cannot avoid mtgox because it's the only source of data for the first years. But then as soon as the other exchanges come in we are going to use the median between them.
The indicator must be overlaid on another chart. And I use the forex usdeur which I then hide (If someone has a better idea, maybe something which is open 24/7, I would be happy to hear it).