Bitcoin and Ethereum still become the most popular crypto in next a few years because others altcoin can not replace it yet. Both coin has potential to going up by multiple times because these coin has the biggest community and the strongest fundamental.
Even I believe Bitcoin will be the trend setter in the year 2019. This has so many reasons and besides all other, one is that no other crypto in the market has enough status and potential to outshine Bitcoin. This currency has gone a long way and despite hurdles in the way is still the leading one. If all the countries embrace the technology, I hope that it will be the future currency that will even push aside USD.
There are some cryptocurrencies which are very popular and on the top of crypto list. Bitcoin is still on the top although its price is very low these days. Ripple has increased its position and holds second and third position in the list, and finally Ethereum is also a good choice for investment in these days. For these three coins are the best for investment in 2018.
The price of every market is very low based on their previous ATH and not just bitcoin. Moreover, what you are focusing on the more is just the market cap but there is more to that when it comes to a market staying on top of its game with a lot of it having to do with the team, the product usage and so on, not just about some speculated price.
Bitcoin will still remain on top with a great community and there is nothing anyone can do about that. In the given time frame, eth or any other coins also may try to match the marketcap of bitcoin with their unregulated supply but no one could beat bitcoin price levels as of now as all altcoins are still lagging with real time applications.