All I know is the ratio of Silver to Gold is at another extreme relative to the norm. It has been having these run ups every even year for some time now and ends the same way with the price of Silver falling much faster than Gold. Silver has a much higher beta than Gold so consistently does this on run ups and then sell offs. So the spread trade would be SI/GC with the idea that a sell off will see Silver fall much faster than Gold coming back to a normal ratio as it has in the past.