Actually the whitepaper gives lot of information about the upcoming project based on blockchain technology. Whitepaper is the introduction between the project and the investors, at the time of reading whitepaper it must elaborate highlights of the projects like what their project can do, what problem they are solving and why they are using blockchain. if you find these information than you can go for further steps on making investment decision like researching about Team, Community, Token matrix, Marketing & ratting on trusted sites and by trusted influencers. In short I don't rely on whitepaper only for making my investment decision.