Also, I admittedly missed another provision of the poison pill - the board also has the ability to exchange an unexercised right for 1 share of common stock, effectively doubling outstanding shares for eligible shareholders without them needing to make an additional purchase. This may be more
[0]: https://www.sec.gov/ix?doc=/Archives/edgar/data/1418091/0001...
The market cap stays the same (nothing about the business has changed) but suddenly there are 185 shares. So the new price per share on the open market is 1,000/185 or $5.41. So just buy the extra shares you can buy and you should be able to sell them on the open market for a profit. The only person who loses out is Musk, would now owns ~half as much of Twitter as he did before.