The abnormal return in an event study is described as the:Multiple Choicetotal return earned on a security on the day of an announcement.esdaily return on a security minus the daily return on the overall marketaverage return on a security for the $7-$day period surrounding an announcementaverage return on a security for the $7-$day period surrounding an announcement minus the average retur on the security for the past year.daily return on a security on the announcement date minus the risk$-$free rate of return.