<P> BHAR - the buy - and - hold abnormal return for rm i in the period between months t and T </P> <P> R - the return of the rm i in month t </P> <P> R - the return on the matched (benchmark) portfolio in month t </P> <P> In order to test the statistical significance of the results (1) the average BHAR (ABHAR) needs to be calculated and (2) t - test needs to be applied . The formulations are as follows: </P>

Buy and hold involves buying stocks and holding them