Some goldminers hold bullion as an asset - for example SLR holds bullion and cash Therefore they should go down more %age wise than their fellows who only hold cash
There is no percentage to go down on with gold held as an asset, because when it was mined, it was not sold and therefore not technically part of the P&L. Therefore companies with gold assets are worth a lot more than companies holding cash as most people would not pick up their true worth.