Fertitta, who now owns 6.9 million shares of Wynn, has become the second-largest individual investor in the company, after Co-Founder Elaine Wynn.
Shares in the operator rose 11% to $64.64 at 11:10am in New York trading on Monday.
Fertitta, owner of the Golden Nugget casinos, the Landry’s Seafood chain and NBA franchise the Houston Rockets, has an estimated net worth of around $8bn.
The 65-year-old has a deep understanding of the gambling industry, having sold Golden Nugget Online Gambling Inc. to DraftKings Inc. for $1.56bn.
Wynn had previously relied on its Macau properties for the majority of its revenue, but the region has been heavily impacted by the Covid-19 pandemic and the subsequent lockdowns in the area.
There has been mixed news from the city this week, with the Macau Government announcing a new round of testing after a dealer allegedly tested positive for Covid, with three further people subsequently returning positive results.
Despite the outbreak, China is pushing ahead with plans to re-open the smart visa facility from 1 November for Chinese nationals coming from the mainland.
The re-opening allows visitors from the mainland to apply for visas individually or in groups to travel to the Chinese gambling province.
Last month, Fertitta said he was looking to build on the Las Vegas Strip, with the Houston-based billionaire planning to build a 43-story, 2,000-room hotel and casino on priorly purchased land – which initially cost $270m.