Question 1

What does this event study tool compute?

Accepted Answer

Abnormal returns (AR) around an event, averaged into AAR and cumulated into CAR and CAAR, using a market model, market-adjusted or mean-adjusted benchmark, with cross-sectional t, Patell, Boehmer-Musumeci-Poulsen (BMP) and generalized sign tests over the event windows you choose.

Question 2

What data do I need?

Accepted Answer

A returns table (firm, date, security return, market return) and a list of event dates (firm, event date). You can also paste prices and let the tool convert them to returns. Everything runs in your browser — nothing is uploaded.

Question 3

Is this investment advice?

Accepted Answer

No. It is a research and teaching calculator for the academic event-study methodology only. It does not provide trading signals or investment advice.

Event Study Calculator — abnormal returns made simple

1 · Your data

2 · Method

Results

Cumulative abnormal returns by window

Daily average abnormal returns