In an event study, the abnormal return is described as the

Multiple Choice

total return earned on a security for the $7-$day period commencing three days prior to an announcement affecting that security.

actual return on a security minus the market rate of return on the same date.

change in market value of a security on the day of an announcement affecting that security.

total return earned by a security on the date of an announcement affecting that security.

any change in the market price of a security that exceeds five percent over a $7-$day period.

The efficient market hypothesis implies that

Multiple Choice

efficient markets will tend to have fixed prices from one day to the next.

stock prices are only efficient when all investors review their portfolios daily.

any investment should earn a normal return commensurate with the investment$$s risk.

investors must be disinterested in their investments for the markets to be efficient.

all investments should earn the same average rate of return over time.