The ICO mania definitely contributes to this, but so does the worry about a Bitcoin split. I've read a lot about it and could not give you a coherent answer of what is likely to happen and what would be the impact if it does or does not happen. So people like me (probably in top 5% of knowledge among Bitcoin holders about the technical aspects) put holdings in other coins to wait and see.

The coins that stand to benefit most from this are the ones traded on GDAX -- Ether and Litecoin. And Ether has the most breathless hype going for it right now. And this is the same advice I give to the non-technical people in my life who've jumped in late and don't have a Poloniex or Bittrex account to trade other coins (sign up for GDAX, balance things with a wait-and-see attitude towards August 1st).

BTW - my 89 year old farmer grandpa who can't even get wired internet at his house now has a crypto portfolio, in case you're looking for bubble indicators. (And if you ask why my advice wasn't to avoid an investment you don't understand -- well, I am bullish on crypto long term and they really wanted to get in, and view it as a gamble, so . . .)