(Bloomberg) -- Beyond Meat Inc. shares are on the rise again and short sellers are feeling the burn to the tune of half a billion dollars.

Short sellers are down $534 million in mark-to-market losses since Beyond Meat’s initial public offering last month, Ihor Dusaniwsky, managing director of predictive analytics at financial analytics firm S3 Partners, said in a message. Bearish bets in the faux meat company are at $799 million with 5.3 million shares shorted, according to S3 data.

With the stock up 11.4% in late morning trading Monday, short sellers are left more than $70 million in the red today alone, Dusaniwsky said.

Makers of real meat, like Tyson Foods Inc. and Pilgrim’s Pride Corp., are also getting burned as summer barbecue season gets underway this week and Beyond Meat kicks off sales of its “Beyond Beef” plant product meant that’s meant to look like ground beef.

Tyson shares slipped as much as 3.7% intraday while Pilgrim’s Pride fell as much as 4.6%; Sanderson Farms Inc. tumbled 5.6% for the biggest drop since December. Sanderson and Pilgrim’s Price have underperformed by roughly 6% each since Beyond’s IPO on May 1.

With its own veggie burger in the works, Tyson’s stock is the lone outperformer among so-called “protein” names, gaining 5.8% since May 1, even as concerns over feed costs weigh on chicken producers.

--With assistance from Lydia Mulvany, James Attwood and Bailey Lipschultz.

To contact the reporters on this story: Cristin Flanagan in New York at cflanagan1@bloomberg.net;Janet Freund in New York at jfreund11@bloomberg.net

To contact the editors responsible for this story: Catherine Larkin at clarkin4@bloomberg.net, Scott Schnipper

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