in general the market follows the price of Bitcoin. And the reason is quite simple, Bitcoin is still the main gateway to the cryptos.
It's the first. It's the biggest. It is the safest and most tested. Everyone will always organize their strategies by looking at Bitcoin.
That is always the thing, bitcoin tend to make the whole market what it is in terms of its movement and most times, it is how the bitcoin market moves that would determine the lane most traders will want to be taking in the market to their favor judging by the reactions on the chart at that point in time. We know there are actually selected few altcoins that tend not to go too far down in most cases, or tend to stand out from the general market movement, but if we are to look at it on the large scale, I will say majority of them move based on the general sentiment in the market with most of it having to do with bitcoin.
Many people are speculating like we are going to see what we had experienced in late 2014. But, all the leading coins are posed to have massive growth in long run hence, I believe that I never need to worry for my decision of adopting cryptos for my rest of life.
In 2014 and 2015, we had 1/5 fall down where in 2018 so far we have seen 1/3 fall down from ATH in both the scenarios with respect to bitcoin price movements. It might mean that there are still down trend and almost all the altcoin may follow bitcoins in coming weeks. It would be hard to filter out a coin which is resistant to bitcoin's fluctuations as there could be no guarantee that it will remain resistant to bitcoin's all the times.