I think gold is underprice regarding the four other metals. If on average prices up plus or minus in many cases a factor of 20. A millionaire from the 1970s needs $20 million today.
So Silver at $1 back in the day, $20 makes sense today. Gold was trading at $140/oz. times 20 is $2800 today. So to me? Gold has the best potential. Pretty much all the metals are under priced, AG Plat, Pall even CU and aluminum.
If Gold went to $2800, Silver naturally could double, or more.