Give gold bugs their due. The yellow metal has been a light in the investing darkness. At a recent $3,406 per troy ounce, it’s up 30% this year, to the envy of stock, bond, and Bitcoin holders.

The moment gold investors eagerly anticipated finally came to fruition on Tuesday when the price of the precious metal rose past $4,000 per ounce, a record high. That came on the heels of numerous ...