Nothing surprising about rio and bhp taking it on the chin as big base metal producers. Demand is contracting particularly in China who has keep base metal prices propped up for years. They currently have huge stockpiles and will likely not be buying the quantities of the past until the global economy turns around. This article on Reuters caught my eye a few days ago.
No, it is big money manipulation to drive down the market so they can accumulate shares at much cheaper price. They will eventually drive it up and accumulate short positions. I warned about this in IBM, APPL and X message board since Feb-March.