Nearly four out of every ten UK takeover announcements last year were preceded by suspicious trading activity, according to the Financial Conduct Authority’s latest market cleanliness statistics. The 37.8% figure for 2024 represents a five-year high and a sharp jump from 30.3% in 2023.
For context, this metric sat at roughly 10% back in 2018. In six years, the rate of abnormal share price movements ahead of takeover announcements has nearly quadrupled.
What the numbers actually measure
The FCA’s Market Cleanliness Statistic, or MCS, tracks abnormal price movements in target company shares before takeover announcements become public. When a stock inexplicably surges right before a buyout offer drops, it raises the obvious question: who knew, and when did they know it?
The FCA itself is careful to note that its statistic is just one measure and does not definitively prove insider trading. Abnormal price movements can result from legitimate speculation, analyst predictions, or even coincidence.
