China's sole pure-play silver fund, the UBS SDIC Silver Futures Fund LOF, plunged 10% on Thursday, ending a speculative rally. This follows weeks of significant gains, with spot silver reaching record highs. The fund manager had issued multiple warnings about unsustainable gains and a high premium over underlying assets. In response to the frenzy, the manager tightened subscription rules and reiterated concerns about potential steep losses if silver futures reverse.