Its called being made inside and the restrictions that brings, happens every day in the market for many reasons including placings, takeovers where major shareholders support is needed etc. Inside information isn't illegal, sharing it or trading off it is
Don't forget most oilers are down today so I wouldn't read to much into the SP action today. Expect to hear more about the deal in the coming days and weeks
Have a look at the low CERP hit recently (0.92 from memory) all oilers took a huge hit and now starting to recover. CERP was high risk due to their size and was somewhat a binary bet themselves
Actually I am one of the largest shareholders in CERP and have given my support to this deal by signing an IU, I see this as a good deal for both companies