The trend since the peak on 2017 is going down. There were few bumps and ups but still it is a down trend. This month the lowest price of ETH was around 400$ and now having a resistance not to go below 400$. Consider the trend of the whole cryptocurrency market. Bitcoin's price goes down and most of the other coins goes with it. Bitcoin has fallen down again since it reached the 8000$+ mark. If Bitcoin will fall down deeper around 3000-4000$ then we can expect the price of ETH around 200$ too. Also the people are more focused on Bitcoin, the attention falls off even though there will be a significant update to ETH.
That 400 mark is where I'm going to lose all faith in ETH. It's been bouncing off it a bit and might even break through. If it does, I wouldn't be surprised to see 300 next. There doesn't seem to be anything breaking its downtrend. It's just bumping down in a sad and miserable way, with nothing to hold it up.
What happened with all of the coins the developers were pumping back in? That's probably one of the reasons it's devaluing. And also because it doesn't have much of a future without a faster transaction speed.