This article explains why few attempt to attack shorts on comex
http://investmentresearchdynamics.com/how-come-no-one-will-attack-the-comex-gold-short/
and this is abit longer but is more recent explains how the shanghai gold exchange is a potential game changer for true price discovery
http://www.minyanville.com/business...etals-investing-china-chris/5/6/2016/id/56877