This paper examines the sources of pre-bid announcement abnormal returns (ARs) accruing to target companies’ shareholders. To control for publicly available information, targets are classified as either identified or unidentified. The paper finds that prior disclosure of bid related information does give rise to pre-bid ARs. For identified targets there is no evidence that these ARs arise from trading on unpublished price sensitive information. For unidentified targets, trading on unpublished price sensitive information may give rise to ARs, although these ARs could be explained by stakebuilding. ARs do not occur prior to the first bid news item, a result contrary to previous US studies.