Miners to gold ratio is a leading indicator for PM sector. It represents market valuation given to miner for the price of gold. As valuation rises the miners go higher.

It has not failed.
In Jan- Feb of 2016 it signaled major bottom for the PM sector.
In July it again it signaled that correction is beginning.
Now it is about to signal a breakout from an inverse HnS for another RUN in PM sector similar to first half of 2016.