As a lazy reader, could I ask those posters that use linear models for prediction to just say so, for example use tags as: [Linear prediction based on the last five years for bitcoin value]. Since I can make easily that prediction by myself I am not going to extract much value with your linear prediction. Anyway that prediction reflects what you are interested in or what is interesting for you, or what you consider could be interesting for the rest of us. That is the answer to another question: What do you think is interesting for us.