Home / Event study statistics / Corporate governance filings
Corporate governance filings
n=764as of 2026-07-09
Filings on directors, supervisors and governance structure.
| Window | Benchmark | n | Mean abnormal return | Median | q value | Significant |
|---|---|---|---|---|---|---|
| Event day | BHAR | 613 | +0.40% | +0.03% | 0.022 | Yes |
| 5 trading days after | BHAR | 605 | +1.82% | +0.38% | 0.000 | Yes |
| 20 trading days after | BHAR | 313 | +3.39% | +0.34% | 0.007 | Yes |
Method: the filing's public-availability date is day 0, with a conservative entry on the following trading day. CAR (cumulative abnormal return) is estimated with a market model and calibrated by a placebo test that keeps the event dates but draws random same-day tickers. BHAR (buy-and-hold abnormal return) is measured against size- and liquidity-matched control stocks. All tests carry a multiple-testing correction (BH-FDR). Where the two benchmarks disagree, both are shown as they are — we do not pick the flattering one.
Frequently asked questions
How do Taiwan share prices behave after a corporate governance filing goes out?
Across n=764 historical events measured by this site's event study engine, mean abnormal return +0.40% on the event day (BHAR benchmark). Both CAR and BHAR benchmarks are presented, flagged where they disagree. This is not investment advice.
How large is the sample when a corporate governance filing goes out?
764 events, as of 2026-07-09, of which 4 statistical cells clear the significance threshold.
Other event categories
The above is a statistical view of historical events (base rates). It is not investment advice and not a trading signal; a historical distribution does not guarantee the future repeats it. Source: This site's event study engine (computed in-house from official public-source event data; editorial copyright)