Supply preceeds demand.
Discussion
The expectation of future demand is what creates supply.
Expectation is only for things that haven't arrived. As in, it's not there. The future doesn't exist. It is expected.
The *expectation* does exist, though, in the mind of the entrepreneur.
Anything can exist in a mind without it actualizing into physical reality. Not great to plan on the whims of the mind.
My perception: Demand is a void into which supply flows. Demand is market potential. It can exist without inventory. Supply is also independent of demand. They can each exist without the other. But when they exist in play with one another you get a market where there can be price action as each increases and decreases.