premise: 
  Dominion Textile Inc. holders adopted a shareholder-rights plan at the annual meeting.
  The so-called poison pill took effect Aug. 9 pending ratification by holders. Rights attached to the company's common shares were issued that are triggered if a hostile bidder acquires more than 20% of the shares outstanding. Once triggered, the rights allow holders to buy additional shares at 50% of the then current market price or, at the board's discretion, to receive securities or assets.
  Separately, Dominion Textile posted net income of 4.7 million Canadian dollars ($4 million), or 12 Canadian cents a share, for the fiscal-first quarter ended Sept. 30. The company had a net loss of C$2.3 million, or 14 Canadian cents a share, a year ago. Sales were C$348.2 million compared with C$307.2 a year earlier.
  
   What can shareholders do if the rights are triggered?
hypothesis: buy additional shares at 50% of the then current market price