I view silver as kind of a leveraged play on gold. Some people are all ape shit about mining stocks for this purpose, but I think the odds of them being nationalized are high when metals do start to skyrocket, so you would just be giving your money away to the government in miners. So for me, silver is mining stocks without the counter party risk.

You can make money in platinum like any other commodity, and it's entirely possible some random billionaire or government pumps it by stockpiling for strategic reserve, but in terms of potential upside, other gold alternatives don't really seem to be offering anything above and beyond what silver already does.