In this paper, I study trading activities prior to M&A announcements pertaining to the rivals of the merging firms. I find that not only acquirers and targets experience increases in abnormal trading activities in stock and option markets, but also their rivals. The rise in option trading is...

We find strong evidence that net insider selling is positively associated with future stock return volatility, consistent with insider selling increasing outside investors' uncertainty. The positive effect of net insider selling is significantly stronger when the volatility is measured around...