Mergatroyd.

A lot has to do with the buying volume at any particular time. If theres been a big sell off for whatever reason, afterwards, when a bottom is formed this stock like others trades until the over hang of shares is mopped up by buyers. Sometimes it happens quickly ie on high volume, other times it happens after a spate of sideways trading or what is often described as climbing the wall of worry.

GPR does seem to loosely follow silver, but at the same time there are buyers getting in a different prices and sellers selling (sometimes the specialist or other market makers going short to create a liquid market) which muddies the picture .