The Barstool Sports founder kicked off his daily day-trading broadcast on Twitter by tearing into Wolfpack Research short-seller Dan David, who slammed him Tuesday for touting what David called “less than worthless” shares in the tech firm Remark Holdings.

Calling David a “fraud” and a “used car salesman,” Portnoy said he’s dumped all his Remark shares and denied that he’s pushed the stock, which trades under the ticker symbol MARK.

“Now I wanna buy MARK because this guy’s clearly in cahoots against them,” Portnoy said after reading from The Post’s Tuesday report on David’s concerns about Remark, which include alleged ties to a blacklisted Chinese company.

“And by the way, MARK’s up because nobody gives a f— what this guy, who looks like a f–ing doo-doo face, says,” Portnoy added in a five-minute video that’s racked up more than 94,000 views on Twitter. Remark shares climbed slightly in early trading Wednesday but were down roughly 4.3 percent at $1.78 as of 1:19 p.m.

David fired back from his firm’s Twitter account, calling Portnoy “a pumper scumbag wearing pajamas.”

“When Davey is challenged and knows he is wrong, it’s always the same,” David told The Post in a statement. “He throws around odd insults followed by touting how rich he is. He does zero diligence and provides no specific rebuttal to any of our research.”

Noting that he’s called Remark’s shares the “WOAT” — or “worst of all time” — Portnoy said he hasn’t told anyone to buy them in roughly three months. But he didn’t mention that he boasted about the stock’s gains and his decision to hold onto it three weeks ago.

“Those who stay will become champions!” he said on July 23. “Never sell!”

Neither Barstool nor Remark immediately responded to requests for comment on Wednesday.