Well... 12.75% of the worlds gold is theoretically held in Fort Knox. If all that gold (or a significant portion) was discovered to be missing, it seems logical that a revaluation of gold higher would be necessary... but by how much and according to what market factors is a tricky question.

If demand stays the same, but the known supply is smaller, it seems gold would go higher.

But, all of current demand is satisfied by the actual stockpiles already. Knowing there is less than we thought only plays out psychologically.

So. I am going to assume that a temporary psychological shock would momentarily increase demand, rising prices by 10% or more... and then it would settle back down as market fears calmed.