Contents · 38 / 58
Conduct Corporate Event Studies
Updated 31 October 2026 · 3 min read · 14 Contents
Plain-language meaning
Corporate event studies measure what one listing's price did after each of its own past events, such as results, dividends, corporate actions, filings and insider disclosures, at fixed horizons of 1, 5 and 20 sessions.
Why it is useful #
They turn 'how has this stock moved after results?' into a dated, countable history, with each outcome compared with the exchange benchmark, instead of relying on memory of a few notable reactions.
Where it appears and the workflow #
Open Event Study (/EventStudy). Choose the exchange and symbol, then select an event family: results, dividend, corporate action, filing or insider disclosure. The page studies the last five years and lists each event with its forward returns, and a summary of the outcomes. Analysis requires the advanced-research entitlement.
Calculation or source #
Events come from persisted results, dividend ex-dates, corporate actions, corporate filing events and SEC insider forms. For each event, the forward return is measured from the close of the session before the event at 1, 5 and 20 sessions, and the excess return subtracts the benchmark index's return over the same sessions.
Prerequisites, inputs, period and unit #
Prerequisites are stored events and stored daily bars for the listing and its benchmark. Horizons are sessions; returns and excess returns are percentages.
Worked example #
Illustrative only: across 18 results events, the 5-session summary might show a median of +0.8%, a mean of +1.1%, a middle half between −2.0% and +3.4%, a median excess of +0.3%, and 11 positive, 6 negative and 1 pending outcome.
What high and low mean #
A higher median or mean means the stored outcomes after that event type were larger on average in this sample. The spread between the first and third quartiles shows how varied they were.
Positive, negative and zero #
Positive, negative and zero describe each forward return or excess return. Pending means the horizon has not matured; unable means the required bars were missing.
Limitations and common mistakes #
Small samples, overlapping events, changing market regimes and survivorship can mislead. Event dates follow the stored source and can differ from when news first reached the market.
Market-specific differences #
Event families and benchmarks follow the listing's exchange; insider disclosures cover the regimes that are stored for that market.
Suggested next steps #
Run the results family for one listing and record the 5-session median, the quartiles and the pending count. Compare it with the dividend family and explain why the samples are not comparable in size.
Educational use only #
This guide explains descriptive research evidence. It is not investment advice, a price prediction, a recommendation, a claim of predictive accuracy, or an instruction to buy, sell, rebalance or place an order.