Poison pills have been around for decades. The lawyer Martin Lipton, a founding partner of Wachtell, Lipton, Rosen & Katz, invented the maneuver, also called a shareholder rights plan, in 1982. It was a way to shore up a company’s defenses against unwanted takeovers by so-called corporate raiders like Carl Icahn and T. Boone Pickens.They have since become a part of the corporate tool kit in America. Netflix adopted a poison pill in 2012 to stop Mr. Icahn from buying up its shares. Papa John’s used one against the pizza chain’s founder and chairman, John Schnatter, in 2018.Investors rarely try to get around a poison pill by buying shares beyond the threshold set by the company, according to securities experts. One said it would be “financially ruinous,” even for Mr. Musk.But Mr. Musk, who is worth more than $250 billion and is the chief execu …
