Hanlon is not alone. Last year’s blistering rally for silver has gone into overdrive, with prices breaching $90 an ounce this week and, despite a pullback on Friday, still up by around one-quarter this year. The metal has now tripled in value over the past 12 months amid wild price swings. Dealers say stocks of silver coins are selling out in record time, while precious metal traders warn of a global shortage.