Stats › Listings, IPOs and corporate actions › Market cleanliness
The share of UK takeovers preceded by a suspicious price move went from 7.7% to 41.1% because the measure changed
| Measure | Jurisdiction | Figure | What it measures |
|---|---|---|---|
| Abnormal price move before takeover, intraday method | United Kingdom | 41.1% in 2025, 37.8% in 2024 | Five minute prices, 48 hour window |
| Abnormal price move before takeover, daily method | United Kingdom | 7.7% in 2021 | End of day prices, two day window |
| Abnormal option volume before takeover | United States | 25.12% | 30 days before announcement, 1,859 deals |
| Abnormal stock returns, same sample | United States | 7.26% | Same deals, price rather than options |
| Abnormal stock volume, same sample | United States | 18.93% | Same deals, volume at the 5% level |
These are not five estimates of one quantity. They differ by jurisdiction, by instrument, by whether price or volume is tested, by window and by threshold. The United Kingdom rows cannot be spliced into a series, and the regulator says so explicitly.
The regulator's market cleanliness statistic reads 41.1 per cent for 2025 and 7.7 per cent for 2021. The two numbers come from different methods, and the regulator states the change is not an indication of any deterioration.
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