Standard & Poor's said Wednesday that it will add Questcor Pharmaceuticals Inc. to its S&P SmallCap 600 index to replace Sonic Solutions, which is being acquired by Rovi Corp.
The date for the index shift will be announced at a later time, S&P said.
Rovi makes copy protection for things such as movie DVDs, and is a member of the S&P MidCap 400. Sonic makes DVD-burning software. Questcor makes drugs for nervous system and inflammatory disorders.
Questcor shares rose 38 cents to $14.56 in aftermarket trading after the announcement, after falling 25 cents to close the regular session at $14.18. Stock added to major indices typically rise on the news because portfolio managers who track the index then need to buy the shares.