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Buyback-related material information
n=73as of 2026-07-09
Buyback-related filings published as material information.
| Window | Benchmark | n | Mean abnormal return | Median | q value | Significant |
|---|---|---|---|---|---|---|
| Event day | BHAR | 59 | +1.31% | +0.49% | 0.028 | Yes |
| 5 trading days after | BHAR | 50 | +4.25% | +2.42% | 0.017 | 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 buyback-related material filing goes out?
Across n=73 historical events measured by this site's event study engine, mean abnormal return +1.31% 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 buyback-related material filing goes out?
73 events, as of 2026-07-09, of which 2 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)