Well it's always a must to read them if you're gonna go invest in the coin/token you're interested with isn't it?
Yes it is, but not many people are doing that. They hear a friend, youtuber (sponsored), banner Ad/Video, etc and invest a big portion of their funds, and when that project doesn't do good in the NEAR future they panic sell, and lose money bouncing around on coins. If you get personal with a project read whitepaper, watch AMA's, Presentations, join telegram groups and follow announcement, check the track history of their promises, Github activity, how involved the community is ALL the things that make you value the project and believe the vision.. then you will think the opposite way, like me I watch a project and I hope that they dont go on a bull run until I obtain my "required balance" lets say 2,500 coins.