The Gold to Silver Ratio looks quite steady now, and when gold goes up, silver does and it seems to stay in ratio somehow (despite one being an industrial metal and one being mostly decorative)
Sometimes it does change, at one stage quite recenlty you could swap 1 ounce of gold and get about 66 ounces of silver in exchange. Now the ratio has changed a bit, it is 61, so you could swap your 61 ounces of silver back and get an ounce of gold in exchange. You now have one ounce of gold (Which is what you started with) and 5 ounces of silver, which you got for nothing.
The good thing is it doesn't matter what the price is doing, going to the moon, or crashing.
The bad thing is there are fees involved.
Physical metals require face to face meetings or trusting the post service.
Unallocated is easier but there are transaction fees which will distort the reported GSR. You need to work out your own Unallocated GSR, currently with fees I am looking at a GSR of 57 not the 61.5 shown on the graph.
I have set an arbitrary GSR at which I will buy silver, anything higher than 55, and another arbitrary value of 65 where I will swap some gold for silver, or 45 where I will swap some silver for gold. I should probably update these if there is a trend forming in the GSR but life is too short.