All investments, food, clothing, fuel, gold, gems, shelter, currencies are subserviant to a loaded firearm.
Gold, treasuries, and currencies are money, not investments. Foreign currencies (gold included) is speculation or a bet against the US dollar. Money is nice to have, but an investment is by definition some thing other than money that are expected to provide a return, like stocks. Or rental income from real estate.
Bat guano is a commodity, I suppose.