USA is number 2 since 3-4 years because the two new superpower actually are Russia and China. Russia is the number 1 owner of GOLD in our planet, and same thing for China.
I am pretty sure that
both Russia and China are not the number one holder of Gold in the world.
Not only that but the value of an economy is based on the goods and services that a country can produce, not how much it has in assets