a day after elon musk said he wanted to take twitter inc private the socialmedia network said it has adopted a shareholder rights plan with a 15 trigger twitter said the socalled poison pill is aimed at ensuring its shareholders an appropriate control premium in the event of a takeover and at giving its board enough time to make informed judgments and take actions that are in the best interests of shareholders mr musk who recently revealed that he had built a 91 stake in twitter on thursday said he had made a nonbinding proposal to buy the rest in a deal that values the san francisco company at about 43 billion twitter which previously said its board would consider the proposal on friday said the rights plan doesnt prevent it from engaging in talks or accepting an acquisition proposal that it believes is in the best interests of the company and its shareholders the wall street journal on thursday reported that twitter was considering adopting the poison pill which is slated to expire in a year after jumping more than 10 in premarket trading thursday after mr musk revealed his proposal twitter shares ended the regular session down 17 to 4508