Twitter is trying to thwart billionaire Elon Musk’s takeover attempt with a “poison pill” — a concoction that companies have been wielding against unwelcome suitors for decades. The ingredients of each poison pill vary, but they all designed to create an option for corporate boards to flood the market with so much newly created stock that a takeover becomes prohibitively expensive. The strategy was popularized back in the 1980s when publicly held companies were being stalked by corporate raiders such as Carl Icahn — now more frequently described as an “activist investor.”
