It's true that if your measuring stick is toilet paper, the current price of Bitcoin doesn't tell you much.

> b) has been up till now

Past performance is no guarantee of future ... etc

Sure, that's what every traditional investment prospectus says in the first paragraph. They usually then proceed to explain how well they've been doing and why you should therefore invest.

There is something called Baye's rule. Ignore it at your own (opportunity cost) risk.