since 16th April (issue date of the placement) 100m shares have...

since 16th April (issue date of the placement) 100m shares have traded. That represents 18% of the placement. As a rule of thumb I reckon that you need 20% of the placement stock to trade before you see the traders gone and the price rising again.
Based on those calculations we need another 12 mill shares to trade. On current daily volumes that's about 7 trading days.
It is'nt a hard and fast rule but it's a guide of sorts.
Good luck and good punting.