"Stock To Flow Model" (Bitcoin) is inherent above all precious metals. This model relates the "Stock" (current available stock) and the "Flow" (of this asset must be produced in the year. In this case the asset is Bitcoin and we know that every 4 years, due to Halving , this value is halved).
Taking an example with gold we would have: gold mined so far in relation to what will be mined until the end of the year.
Ratio between Stock and Flow gives a coefficient, the greater the value reached (high ratio) the rarer the asset in question (the asset in circulation will be much greater than what is extracted).

Another important concept is that of the "Market Value": that is, the total value of the asset (Bitcoin) available (Stock multiplied by the unit price of the Stock itself. Valorisation of the world stock of this asset).

The Market Value is related to the Stock To Flow: that is, the scarcity is directly related to the total value of the asset itself. The main limitation of these models is that Bitcoin's request is not taken into consideration.