David Einhorn has denied that he had posted about Herbalife Ltd. on Twitter, claiming that he has an impersonator in the social media site.

Einhorn, who is also the founder of Greenlight Capital, was alarmed by a tweet on his previous Twitter account called @Greelightcap that seemed to show that he was picking sides in the war between Carl Icahn and Bill Ackman, the two investors who have opposing stances in Herbalife.

Einhorn had already suspended that account long before the tweet. He has been only making infrequent tweets under @davidein which tend to be only about poker.

Social media sites are becoming the new medium of hoaxes as many investors use them to gain important information about stocks.

Late in January, Sarepta Therapeutics Inc. and Audience Inc. saw dramatic drop in their respective shares following posts in Twitter that were purported to be from short-selling researchers.