OK. So, I would like to set up a forecast model for Bitcoin price. I have ideas on what independent variables impact the price, but I'd like to ask a crowd just in cast I'm missing something.

The model would like this:

Bitcoin's price (today or tomorrow) is a function of X1, X2, X3... Xn.

So, please chime in with the following what is your thought on an independent variable (X1) that impacts Bitcoin's price? Does the variable impact today's price, tomorrow's or both? Finally, and most importantly is the variable quantifiable and what is the source of the data? Why?

I'll give an example - X1 is Bitcoin's available supply. The available supply impacts today's and tomorrow's price. The available supply is quantifiable and the data source could be obtained from blockchain. Quantity supplied impacts price (or exchange rate) - basic econ 101.