I have been buying of late too. Started at $18 now with ACB low $16s. Booked some losses on OVV which is up 4x from March lows to buy SU at March lows.Suncor has been really hit - apparently many funds, who typically would have both SU and CNQ, have been shedding SU and in some cases shorting and going long CNQ. CNQ seems to be more popular because they are not exposed to refining margins, not suffering under a low price differential anymore, and are proving to be the low cost leader and also now the largest oil and nat gas producer in Canada.
But Suncor will be around too and I've been adding to my previous positions at $15 and $16 in the last few weeks, in addition to the shares I bought back in March/April. Suncor may take a bite at something in the next few months too like CNQ did with Pony.