Watson Pharma Volume Spikes

Comstock | Getty Images

Trading volume in Watson Pharmaceutical rose 244 percent over its 10-day average, a day after reports cited the generic drug maker is in talks to acquire Swiss rival Actavis for about $7 billion.

Here's a look at other stocks in the S&P 1,500 index displaying unusual volume in Thursday's trading session.

Follow Giovanny Moreano on Twitter:@giovannymoreano