It's a global pyramid scheme
Alan Greenspan equated it to continentals and greenbacks in the Civil War era and called it fiat currency. Of course the US currency IS fiat currency - it is backed up by the trust that the US government will be around not by any value of gold. The value of the dollar has gone down 93% since 1913.
I am not 100% sold on Bitcoin - though the blockchain concept and cryptocurrencies have appealing sentiments to me.
I treat it like penny stocks. This last week BTC rose to over 7,600 per 1 Bitcoin, fell to under 5,700 last weekend and now is back to almost 7,900 as of 5 pm (11/16). In terms of the grand scheme though it has increased in value 10x in the past year. There were some 'forks' and this caused much consternation so it was not a perfect ride for many but some were making money off it as a speculative tool. Others appreciated it as a means of transaction.
Ethereum had some issues with password recovery and also saw a drop.
If we're on the subject of pyramid schemes I see there is an altcoin called 'TrumpCoin'