By Carolina Mandl

NEW YORK, July 23 (Reuters) - A surge in shares of residential real estate platform Opendoor Technologies OPEN.O has been boosted by the portfolio manager of a small Canada-based hedge fund, Eric Jackson.

Opendoor's stock has soared more than 400% this month, luring retail investors in a fashion that resembles the meme stock frenzy of 2021, when small investors drove up shares of video-game retailer GameStop GME.N and cinema chain AMC AMC.N.

"When I first started tweeting about Opendoor last Monday afternoon, I definitely wasn't thinking it was going to be considered a meme stock," Jackson, founder and portfolio manager of EMJ Capital, told Reuters on Wednesday. "It's a real business. It's not just investors pinning their hopes on some fake crypto coin."

With a market capitalization of about $1.7 billion, Opendoor connects buyers and sellers of houses.

Jackson, based in Toronto, said last week on X his hedge fund had taken a position in Opendoor, forecasting the stock would hit $82 in the longer term.

Since then, he has been voicing his bets on the company almost daily. The stock closed more than 20% lower on Wednesday at $2.29.

He believes Opendoor is a story similar to used-car retailer Carvana CVNA.N, which was considered a meme stock, but started to show improved performance in 2024 helped by cost-saving measures.

"We think there's a big turnaround ahead," said Jackson, whose number of followers on X has doubled in recent weeks to 67,000.

Jackson's profile contrasts with the online influencer Keith Gill, known as Roaring Kitty, an office worker who started to analyze and invest in stocks while unemployed in 2017. His online publications drove the GameStop mania in 2021, causing losses to hedge funds betting against the video game retailer.

Before founding his firm in 2017, Jackson, who has a Ph.D. in management from Columbia University, was a managing director at SpringOwl Asset Management, an activist hedge fund that was a vocal investor in Yahoo during a period when it held a stake in China's Alibaba 9988.HK.

Gill, Carvana and Opendoor did not immediately respond to a Reuters' request for comments.

Jackson said EMJ manages less than $10 million and declined to provide the exact figure. Current assets represent a fraction of the firm's size at the peak, when it was "well over $100 million," he said.

The portfolio manager said a key investor in the fund redeemed his capital in 2022 after the fund posted losses in 2021 and 2022, causing assets to drop drastically. "We were facing shutting the doors," he said.

But instead, Jackson decided to refocus his firm, building machine learning and artificial intelligence models with the help of four engineers to pick stocks.

Currently EMJ's portfolio is comprised of only long positions in a few stocks. The hedge fund, which is a long/short fund, is also invested in bitcoin miners Iren IREN.O and Cipher Mining CIFR.O, quantum technology company BTQ Technologies BTQQF.PK and ethereum ETF ETHA.O.

"I am not interested in stocks that go to zero," Jackson said, explaining why he is not betting against stocks. "The best AI results we've had, it's around these stocks that have this chance to go 10x or even 100x."

(Reporting by Carolina Mandl in New York; Editing by Megan Davies and Jamie Freed)

((carolina.mandl@thomsonreuters.com; +1 (917) 891-4931;))