Volt the NCM chart looks similar to BHP (perhaps more of a megaphone for BHP).
Also a street observation on Ag. For the last 7 years when im in Perth i have been wondering down the the mint and buying a 1oz Au coin and a 1Kg Ag bar. The mint was also a dingy place and mostly only me and a few Asian buyers for investment metal (ie non jewelry).
Recently the mint has had major renovations and the bullion purchase area looks more like a bank with tellers. It is flooded with "round eyes" like me buying big bars of Ag. In my mind the ALARM bells are ringing.
I think a major correction is immanent for the next major move up. In any-case i still bought my usual 1kg bar and a couple of 1 oz Ag Kangaroos. I know i have paid too much again.