Speculation comes from the word speculate, or speculating, which means to be rumoring or predicting something to happen with no hard evidence to back the claims.
On the flipside, speculation also happens to be a powerful psychological driver of pricing and valuation. Speculation of high prices at some point in the future is what brings attention and creates a reflex feedback loop of value accrual across many industries. A reflexive feedback loop is a principle of human behavior , in which the more people that buy in, the more people that will buy in (a self fulfilling prophecy.)