Cumulative Abnormal Returns A study analysed the behaviour of the equity prices of firms that had lost monopoly cases. Included in the diagram are all firms that lost the initial court decision, even if the decision was later overturned on appeal. The event at time 0 is the initial, pre-appeal court decision. Assume no other information was released, aside from that disclosed in the initial trial. The stock prices all have a beta of 1. Is the diagram consistent with market efficiency? Why or why not?

Transcribed Image Text:

CAR (%) 10 -10 -20 -30 -40 -12 -6 0 6 Time in months relative to event month