Cristiano Ronaldo, the renowned Portuguese footballer, has made a substantial investment in Whoop, a wearable tech start-up, as the company expands into the Gulf region. Although the exact investment amount was not disclosed, Whoop chief executive Will Ahmed described it as “one of the largest if not the largest investment he’s made in a company.” Ronaldo reportedly reached out to Whoop for a partnership after researching the company and its products, demonstrating his belief in the start-up. The investment comes as Whoop is expanding into Saudi Arabia, Qatar, Kuwait, Bahrain, and other international markets, while also focusing on adding Arabic support to its devices. The new investment will be used to develop new products and services and boost engagement with users. Whoop, founded in 2012, provides training, health, sleep, and recovery services, and has raised approximately $405 million across eight funding rounds. Ronaldo joins a list of high-profile Whoop investors, including Patrick Mahomes, Eli Manning, Rory McIlroy, and Michael Phelps. As one of the most recognizable athletes and celebrities, Ronaldo’s endorsement is expected to boost Whoop’s branding and reputation in the highly competitive fitness tracker market, which is projected to reach $116.5 billion by 2028.