The two subjects that Registered Investment Advisors and high net worth investors ask me about are:
VIX or volatility in general
Bitcoin or cryptocurrencies in general
For many investors the decision isn't about "IF" bitcoin belongs in their portfolio, but "where" does it belong in their portfolio (personally, at current valuations I would be cautious, but I think it is still helpful to think about where it belongs). With the growth of passive investing, it is even more crucial to allocate cryptocurrency "investments" to the right risk bucket, or else some of the principles of passive investing will fail.
Bitcoin is NOT a Currency
Despite being called 'cryptocurrencies' they are not like currencies, at least not in terms of where they fit into your asset allocation strategy. While you can buy things directly with them, in some cases, many brokerage accounts have debit cards that can be used - and I wouldn't consider that to be a 'currency'.
The cryptocurrencies are just far too volatile to be considered currencies. They don't behave like currencies - even the most speculative emerging market currencies tend to have far less volatility. They don't respond to news or information flow the way a currency would. Currency based ETFs have been around almost since the inception of ETFs and yet none seem to be generate the excitement and buzz surrounding the possibility of cryptocurrencies.
When thinking about how cryptocurrencies fit into your overall portfolio - treating them as part of your currency or even more dangerously as part of your 'cash' allocations seems far too aggressive.
Bitcoin is NOT an Income Product
https://www.forbes.com/sites/petertchir/2017/09/03/where-does-bitcoin-fit-in-your-portfolio/#21cb9f901fe2
