If you'll look at the 2016 charts you'll see that ETH had two small peaks. If you look closely you'll see that first peak is very similar to the peak in 2017 when ETH reached 0.15 BTC . I would even say that they have almost the same structure. I don't believe in such coincidences. Furthermore, the second peak started to form exactly in the same way. So I'm pretty sure that it is a cycle and it must be finished. When the peak will be finished, the long downtrend will come.
By the way, I think there are a lot of fundamental reasons for ETH downtrend in the future.
1. This coin has a lot of problems and I'm not sure that they will be solved in the nearest future.
2. It was rising only due to the ICO popularity and I believe that this year we won't see so many new coins because:
- There will be new ICO regulations this year
- There are too many coins now and it is obvious that we don't need most of them so the demand for new coins will fall
- After the last drop people will invest less in speculative coins and will look more for the fundamental ones
3. There are a lot of competitors and they are becoming strong. Yes, ETH was the king in 2017 but it will be too hard to save this position in 2018
So, in my opinion, if you're in ETH, you should sell it at 0.14 BTC . If you're looking for some profits, you can buy some ETH now and then sell it. The chance that it will reach this aim is really high