Shareholder rights plans, commonly known as “poison pills,” are arrangements that can be used by companies to stave off hostile takeovers or activist investors seeking to exert control over a company without paying a control premium. A typical rights plan, if triggered, would allow all shareholders except the triggering person to purchase additional shares in the company at a substantial discount. The resulting share dilution makes it significantly more expensive for the triggering person to purchase a controlling stake in the company. Because of this, it is extremely rare for a rights plan to be triggered; instead, rights plans can have the effect of encouraging hostile bidders or activist investors to negotiate directly with a company’s board of directors.