One Quarter of All Public M&A Deals Involve Insider Trading
As if the general public hadnâ€™t lost enough faith in the stock market with recent revelations of rigged deal-making that benefits only a few, a new study shows that 25 percent of all M&A deals between public companies involve some kind of insider trading. The study, conducted by McGill University and New York University, looked at informed trading activity in equity options prior to the announcement of corporate deals. The studyâ€™s abstract states:
For the target companies, we document pervasive directional options activity, consistent with strategies that would yield abnormal returns to investors with private information. This is demonstrated by positive abnormal trading volumes, excess implied volatility and higher bid-ask spreads, prior to M&A announcements. These effects are stronger for out-of-the-money (OTM) call options and subsamples of cash orders for large target firms, which typically have higher abnormal announcement returns. The probability of option volume on a random day exceeding that of our strongly unusual trading (SUT) sample is trivial – about three in a trillion. We further document a decrease in the slope of the term structure of implied volatility and an average rise in percentage bid-ask spreads, prior to the announcements. For the acquirer, we provide evidence that there is also unusual activity in volatility strategies. A study of all Securities and Exchange Commission (SEC) litigations involving options trading ahead of M&A announcements shows that the characteristics of insider trading closely resemble the patterns of pervasive and unusual option trading volume. Historically, the SEC has been more likely to investigate cases where the acquirer is headquartered outside the US, the target is relatively large, and the target has experienced substantial positive abnormal returns after the announcement.