The prospect of three dividends in 6 months is a magnet for the divvy-hunters. Calculating UK p in $A is easy and you can do that yourself, roweman.
I think the rise is driven by revert-to-mean. HGG has been beaten down so long on BREXIT and Janus merger uncertainty that a break upward is entirely possible. The market never trades in straight lines.
Wait for the close.
Ash