We use a sample of 816 diversifying takeovers from 1978 to 2003 to examine whether takeover announcements release negative information about the future prospects of the acquirer's main industry. We find that rivals that are most similar to the acquirer (homogeneous rivals) experience significant negative cumulative abnormal returns (CAR) around takeover announcements. Takeovers that result in negative wealth effects to acquirers are associated with negative abnormal revisions in analysts' forecasts of homogeneous rivals' earnings per share. We also find a decline in the posttakeover operating performance of rival firms. The decline is especially pronounced for homogeneous rivals and for takeovers with negative wealth effects to acquirers. Our findings imply that CAR-based estimates of acquirer wealth gains from takeovers that do not account for industrywide information releases are significantly biased downward.