[netcan]

Prices adjust to reflect expectations. Theoretically, if everyone knew with certainty that prices will increase in the future, it would rise now instead. It would rise to reflect the NPV of the future price at any point where its NPV is highest.

The mechanism that would happen through is just as you predict. People would buy & hold bitcoin. Buying & holding is an increase of demand (buying) & a decrease in supply (holding). These both increase prices until the point where buying and holding isn't any more attractive than buying and holding some other asset with a known future value (like government bonds).

In reality that certainty doesn't exist. Current prices of bitcoin a reflection of all sorts of wild guesses about possible future effects that are dependent on all sorts of things.