Is Cryptocurrency a Ponzi scheme or the world's greatest investment opportuniy?

My younger brother who lives in Bucks County, Pennsylvania has been pounding the table for Bitcoin, Gold and Silver for some time. I've never been a precious metals fan and that has served me well for the past four or five years. I have been a fan of the S & P 500 because many of my clients' well-being is connected to it, and since March of 2009 it's been a big winner. However, "big winner" is taking on a new definition in the cryptocurrency space. Recently I've been reading and watching, what I have time for, to try to gain an understanding of where opportunities may still lie. My brother recommended I join Steemit as part of my due diligence process, so here I am. My thanks to all who share ideas here and to whomever decided to grant me access.

At the risk of boring others with needless biographical information - I've been headhunting as a contractor for investment managers, most of whom manage pension assets, for a long time. Before that I worked in several financial service venues including the start-up of a small, publicly traded bank holding company with three operating subsidiaries. One thing I've concluded from all my vocational experiences is that there is much I do not know. I've always vowed never to be one of those people in life who says "well we've never done it that way before." When I hear that it drives me crazy.

At first blush cryptocurrencies look like a case of who gets left holding the bag when values plummet. They make sense to me as alternatives to paper issued by some government, but the dramatic increases in prices can't be justified simply as exchange rates for fiat currencies. I'm guessing they are also vehicles for moving wealth across borders without some government telling you no. Yesterday I watched an hour long video in which a programmer explained why a few of the cryptos have actual value. Unfortunately the terminology was foreign to me, but my gut reaction was he believed what he was saying.

So I am here to learn. I'm sure it will be time better spent than on Facebook.