I want to answer this question on Homebrew.SE, but I'm at an uncharacteristic loss for words.
One example of the concept I'm trying to describe is gold that had heretofore been sitting in people's jewelry boxes or bottom drawers. With skyrocketing prices, more people became more aware that they were sitting on a valuable resource, and thus brought that resource to market.
For some reason, my brain is trapped on the metaphor of dark matter, which is not apt.
What would you call that untapped inventory? "Untapped inventory"?