Is it just that Cerro's price is now getting closer to the value of the takeover.
Primero's current price is $C6.65.
Exchange rate is $C1.04162 per $A.
1 Primero share will be provided for every 0.023 Cerro shares.
The cash portion of Spinco is worth $0.004 per Cerro share.
Therefore a Cerro share should be worth at least 6.65/1.0412*0.023+0.004 = $0.15 to my way of thinking.