It looks like Ethereum is cooling down gradually after a gigantic rally in the last few months; the value reached a ATH of over $400 weeks ago, while at the moment we see prices hovering (very) roughly around $300. Total marketcap has dropped somewhat from a ATH of $38 billion earlier in june to slightly below $30 billion these days.
Ofcourse, this doesn't mean Ethereum is going to nosedive into the ground. It is most probably simply a mass of traders securing their profits. Imagine if you bought Ethereum 6 months back for around $8 ... It might sound cliché, but holding your stack for 100% nowadays requires some steel balls ... !
However, putting the comment about steel balls aside, I believe even those who bought at the peak ($400) shouldn't pull out their hair in despair; the future of cryptocurrencies looks bright, and with Ethereum as one of the giants in cryptoland, chances are high it is only a matter of time before a new rally dwarfs the last one. It'll however probably takes a few months for everyone who ever bought Ethereum at a certain point in history to see green numbers again in their wallet ... !