June 15 (Reuters) - Investors shorting "meme stock" AMC Entertainment are estimated to have lost about $488 million on Monday after a rally that sent the cinema operator's shares up more than 15%, data from financial analytics firm Ortex showed.
By contrast, AMC short-sellers suffered $1.2 billion in mark-to-market losses for the week to May 28, when small-time traders on online discussion groups sent the stock up about 116%, triggering a phenomenon known as a "short squeeze".
AMC shares were down 0.1% in premarket trading on Tuesday. The stock has surged more than 2,500% so far this year.
(Reporting by Sagarika Jaisinghani in Bengaluru and Sujata Rao in London; Editing by Anil D'Silva)
((sagarika.jaisinghani@thomsonreuters.com;))