Have you noticed the news that coinmarketcap has a higher Alexa rank than the Wall Street Journal? It's insane, but Bitcointalk has a much lower rank, as do bitcoin.org and any other BTC related site. We're not measuring in terms of merchants, we're measuring in terms of speculative events and people are paying so little attention to actual spending that the idea that the price has multiplied by three in the past six or seven months sounds completely insane.
Have you seen the charts recently? No "healthy growth" just random spikes. This isn't mass adoption or casual investors getting involved, but a lot of people either think it is or thinks that these prices are moderate.
There is no question that one of the biggest drive for Bitcoin's rise is its speculative nature. Many of us Bitcoin holders are expecting that its value will really rise in the coming days and weeks so that we are holding it and never converting it to fiat money no matter what.
However, Bitcoin always has this ability to correct itself when there seems to already a bubble happening. This had happened in the past and can happen again anytime...it is just that nobody can be sure at what level will it correct especially right now when the market is experiencing the euphoria right after SegWit plus the fact that BitcoinCash (BCH) is not really affecting the real Bitcoin.