PLS hit 87c post discovery (mid 2016) DFS, construction funding...

PLS hit 87c post discovery (mid 2016)
DFS, construction funding through equity raises with offtake partners, prepayments, etc. Lots of news. Late 2016- early 2017.
Long lead mining equipment and engineering largely completed by the time it did final $80mil equity raise to fully fund construction @ 35c in mid 2017. Low being 31 cents.
Mine completion late 2017- early 2018.

The chart you depicted is mine opening honeymoon period and subsequent decline as mine hits inevitable optimising issues, cost overruns, production fine tuning issues, etc. It coincided with massive oversupply thus the retrace was severe in depth and length (for average post honeymoon decline)

P.s. It doesn't mean LTR will have same depth and length of retrace as PLS. As other factors affect that too (macro, commodity price, funding ease, etc.
But it's hard to find miners that don't go through significant decline between discovery and mine construction start. (Excluding DSO mines, their retrace is much shallower usually).

hopefully that helps identify events on the chart for you