If you use rationality to answer that question, as it was previously mentioned, you would check White Paper, project and team reliability.
Now don't forget that we are in crypto world, and things aren't always up to rationality.
Marketing, FUD & FOMO have an importance that you struggle to find any equivalent in normal life.
But you can still find similar examples IRL: fashion FOMO, discount FOMO (you remember, when you see people on TV fighting in supermarkets to get one of the few discounted articles that they aren't in need...?
).
People tend to think market as an agregation of rational people, but in fact, you can add lots of factors that will turn people into irrational morons.
And from a group constituted of rational beings, you finally find yourself with a group of fools that you can't analize. You can just notice the importance and the direction of the wave, but you don't know when it will start breaking.
I remember to have read an article that was explaining that in crypto world, FOMO & FUD were more important than fundamentals.
If I find it again, I will come back to post it here, as it was a very nice one.
To conclude, hype analyzing should be one of the prerequisite in analyzing which coin to buy.
Note the sole one, but an important one.
