Might be a really stupid and childish question, but how do you understand which crypto sector is going to gain popularity and then capitalization?
Use your common sense, if someone did know that, they would become the next richest person in the world. But very few people have been able to predict things, most of the predictions come in after something starts.
Would be great to hear someone, who was previously owning one of those coins, what made him think "ok I believe this sector is going to rise up", maybe something related to certain news, big investors manifesting interest, or some events in the ""real world"" that could have caused this movement.
Most of the cases start with the owners hyping out their own coins. This is taken up by many naive newbies and they add to the hype even more.
Buzzwords are very common in the economic sector and social media. At one time blockchain was the buzzword - you might remember the terms Cloud Computing, Machine Learning and so on. With advancement maybe these things will rise in future but nobody really knows which one will in reality take off or if you may live long enough to see it take off.
It is better to not dawdle in such stuff, often the hype is fake and worthless. On the other hand, investing in bitcoin is always a good option and an easy to make decision.