"I know there will more time of my life spent off the floor than on the floor," says LeBron James, who is already preparing for life off the basketball court by making investments today.
He's not the only one planning ahead.
"Players are now taking more ownership over decision-making when it comes to their investments," says Courtney Brunious, associate director of USC's Sports Business Institute.
Here are some of the start-ups and more established companies in which James and other star athletes are investing their millions.
Iguodala's team, the Golden State Warriors, plays just across the bay from San Francisco, and the star forward is taking advantage of his proximity to Silicon Valley.
"We have some great relationships with VCs [venture capitalists] out there, mainly Andreessen Horowitz," Iguodala tells CNBC. "They've kind of taken me under their wing and ... showed me some things in the portfolio and how I can integrate my brand into some of their brands."
He has invested in tech stocks like Facebook, Twitter and Tesla. He has also backed electronic trading platform Trumid, Arianna Huffington's new company Thrive Global, health and beauty start-up Walker & Company and Derek Jeter's media platform, The Players' Tribune.
Durant, another Golden State Warrior, says he's following the example of his teammate Iguodala.
The NBA star has been known to hang out with Silicon Valley's A-list and "is laying the foundation for a tech empire of his own," The New York Times reports.
According to the Times, Durant's portfolio includes investments "in tech companies like Postmates and Acorns, in addition to hotels and restaurants and film and television development." And like Iguodala, he's also an investor in The Players' Tribune.
A third Warrior is taking advantage of the team's ties to Silicon Valley: Two-time MVP Stephen Curry.
The star point guard owns an equity stake in CoachUp, a start-up that connects private coaches with athletes. Plus, in 2015, he co-founded a tech start-up, Slyce, with his old college teammate Bryant Barr.
As of June 2017, the 23-time Grand Slam tennis champion is backing Daily Harvest, a food start-up that delivers healthy, frozen meals to your home.
"I invest in businesses that operate with sincerity and integrity and deliver a pure and uncompromised product," says Williams in a press release. "I'm excited about Daily Harvest's future as a female-led business and I look forward to helping more people gain access to nutritious meals."
Williams isn't the only celebrity investing in the frozen food start-up. Actress Gwyneth Paltrow also took part in a round of financing this summer.
The Detroit Lions safety, who plans to double his income by investing, puts 10-to-20 percent of his wealth towards funding start-ups.
While he doesn't disclose all of his investments, Quin revealed three of them to ESPN: superfood company Health Warrior, customizable pet nutrition company pawTree and PeerWell, an app that improves surgery outcomes and recovery times.
The retired New York Yankee, who launched his own sports media company, The Players' Tribune, is also putting money into start-ups. In 2015, Jeter invested in Blue Jeans Network, a video conferencing service.
"When I met the Blue Jeans team, I was busy starting my new venture, The Players' Tribune," the former all-star shortstop tells Business Insider. "I was captivated by what Blue Jeans' video could do to amplify the voice of our athletes."
The four-time MVP is already thinking about life after basketball. "I still have to live life beyond the hardwood," James says in a new video series by Uninterrupted, which he and business partner Maverick Carter launched in 2014.
In addition to co-founding Uninterrupted, which raised $15.8 million in 2015, the NBA star was an early backer of Beats Headphones. When the company sold to Apple for $3 billion, James reportedly earned $30 million.
NBA star Chris Paul is backing WTRMLN WTR, a cold-pressed watermelon juice. "I am proud to join WTRMLN WTR and help shape the way Americans choose their sports drinks," says Paul in a press release.
He's in good company: Beyoncé Knowles is also an investor in the juice start-up.
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