A quick look at the charts of WPL & ROc which shows them at 52 week highs would suggest HDR is due for a quick surge from the current price of $2.28 back to the $2.50 / $2.60 region.
Westpac own 5% now, WPL 10 % and various other chompers with large holdings.
HDR is seriously undervalued by the market at the current s/p.