I didn't read the article posted by escower, but I have traded silver for a very long time.
Sometimes the silver miners lead the metals.
Sometimes the silver metals lead the silver miners.
Sometimes silver leads gold.
Sometimes gold leads silver.
Sometimes the gold miners lead everything
Sometimes SLW leads SSRI, PAAS
Sometimes SSRI leads SLW and PAAS.
Sometimes the HUI leads everything, sometimes XAU
It just depends.
The strongest indicator of a how big a move will be has generally been when SLW or Silver is the leader.