Activist investors are no stranger to the health-care sector, an industry known for binary events and buyouts. In this video, health-care analyst David Williamson discusses two recent news items catching the attention of investors following the moves of these heavyweight activists.

The first is Forest Labs CEO Howard Solomon's announcement he will call it a career as the head of the company. Legendary investor Carl Icahn, who is a major Forest shareholder and has a board seat, has shown misgivings in the past toward management. He has no comment on this news, but he may use the opportunity to exert his influence on Forest's direction.

Obesity-drug maker VIVUS has found itself in the activist investor crosshairs as well. First Manhattan, which controls 9.9% of the company, has been critical of its unpartnered launch of Qsymia and has recruited Icahn disciple Alex Denner, nominating him for the board of directors along with eight others. If successful on July 15, expect First Manhattan to try to shake up VIVUS by aggressively pursuing a partnership or possibly even a sale.

Follow David on Twitter: @MotleyDavid.