On the morning of May 2, JJ Redick was in Philadelphia, preparing for a playoff game against the Raptors; Kyrie Irving was in Boston, prepping for the Bucks; and Chris Paul was in Houston, readying to face the Warriors. By the end of the day, all would become rich. Or, since they are NBA players, incrementally richer.

That morning, when the NASDAQ opened in New York City, one IPO skyrocketed. Its stock had been priced at $25, the top of the range determined by analysts. Trading opened at nearly double that, $46. By market's close the price had hit $65, making it the most successful major IPO since Palm Inc. debuted, in 2000. Within a month the stock hit triple digits. By July it had soared above $230 a share, a rise of more than 800%.

The company was Beyond Meat, an El Segundo, Calif., producer of plant-based burgers and sausages engineered to taste and look like the real thing. The financial world wasn't sure what to think. Some compared Beyond Meat's CEO, Ethan Brown, with Tesla's Elon Musk, two charismatic founders endeavoring to change the image of products—veggie burgers and electric cars—long deemed deeply uncool. Others saw a bubble born of new-age optimism, part tulip and part Bitcoin. Regardless, anyone in on the IPO was sitting pretty.

Among those fortunate few was a cohort of NBA players; in addition to Redick, Irving and Paul, investors included Victor Oladipo, Harrison Barnes and DeAndre Jordan, none of whom, it's safe to say, needed a windfall. Most weren't in it for the cash; rather, they are both converts and proselytizers. Some, like Paul and Redick, eat both plant and animal protein. Others, like Jordan—who was recently in New York hyping the Beyond Sausage Breakfast Sandwich at Dunkin' Donuts—have gone, as Redick says, "full vegan on us."

The NBA connection makes sense, at least in one respect. Today's players are constantly seeking micro advantages. The Lakers traveled with a bone broth chef at Kobe Bryant's behest; LeBron James uses cryotherapy. If a plant-based diet really can extend a playing career—as Brown contends and many believe—then reducing meat intake is worth the trade-off.

From another perspective, however, the idea that NBA players are now the face of veggie burgers represents a seismic shift—both in business strategy and in people's views on food, sports and masculinity.

Redick was one of the first converts. Raised in Roanoke, Va., in a largely vegetarian household, his mother, Jeanie, went back to school in 1993 to become a certified nutritionist. The family served meat once or twice a year, usually at the holidays. The rest of the time, grilling out meant frozen pucks: Boca Burger, VegeBurger, Gardenburger. Redick tried them all. He was not a fan.

The underlying message stuck, though, through his years as a star guard at Duke and into the NBA: What you put in your body matters. Entering his late 20s, Redick began watching his diet more carefully.

Around 2014 or so he met the then 42-year-old Brown, a huge sports fan and former athlete himself. Growing up, he had lived near the Maryland campus, where his father was a professor of public policy. He recalls haunting Cole Field House to watch Terps practices, marveling at Len Bias. Brown played three sports in high school and one season as a 6'5" small forward at Connecticut College before his knees betrayed him. By then, he was already eating vegetarian; he recalls teammates ribbing him during team trips to McDonald's because, well, that's what guys did back then.

After graduating, Brown worked on the science side of clean energy, founded a nonprofit dedicated to land preservation and attended Columbia business school and a public policy grad program at Maryland. Interested in sustainability, he began to focus on diet, convinced that people would embrace a plant-based future—in the end, protein is protein. In 2009, he founded Beyond Meat. The first products hit stores within four years.

From the start, Brown believed athletes were crucial to altering perceptions. He thought back to the 1990s "Got Milk?" campaign, which featured Bo Jackson and other stars reinforcing the connection between animal protein and performance. He needed to do that, but for plants. (Brown recalls that marketing experts told him he should instead target moms, as they did the shopping.) So he hired the guy who created that milk campaign, Jeff Manning. At first, Manning was skeptical—"I didn't quite know how athletes would fit into it," he says. While Brown really believed what he created was a form of meat, Manning thought it better not to identify it as such. After some back and forth they came up with a slogan aimed at both athletes and consumers: The future of protein.

Brown's firepower, then and now, comes from science and history. Speak to him for more than a few minutes and he will take you deep into the weeds, expounding with great conviction upon the five core elements of protein, amino acids, lipids, vitamins, trace minerals, water, and the aging of cells and amino acid scores and then pivoting to Australopithecus Africanus and, eventually, gladiators. As in: Did you know the gladiators—who we can all agree were the most badass athletes ever—ate primarily beans and barley? And, in Brown's view, "NBA players are the modern gladiators."

Now he just needed to persuade them to buy in. When he met Redick, he came prepared, bringing a Maryland sweatshirt in his backpack, thinking it would be funny. (Until Redick said, "F--- Maryland!" and Brown decided not to unveil it.) Redick didn't take much persuading. He liked the food—even those early-generation burgers looked and felt like burgers and tasted close enough. He signed on as a company "ambassador," receiving stock options.

From there, Brown approached other athletes with the opportunity to invest, focusing on NBA players because of their recognizability. As with Redick, he pitched both ethical and environmental considerations and—crucially—the potential performance benefits. He talked about how the main ingredient in Beyond Burgers is pea protein, which digests more easily than meat, making you feel lighter. How the patty provides 20 grams of protein for 250 calories (it also packs 390 mg of sodium), comparable to a meat burger. How it's lower in cholesterol than beef. How it causes less inflammation in the joints. (A 2019 study in Nutrients journal supported the general concept, finding that plant-based diets "may present safety and performance advantages for endurance athletes," noting lower body weight, reduction of indicators of inflammation and cardiovascular protection.)

The fact that eating other healthy, vegetarian foods—like, say, actual plants and beans and nuts—provides the same benefits without all the processing, calories and sodium is both true and, in this case, perhaps besides the point. Part of what attracted athletes was the allure and sheen of a new health product (not to mention a buzzy start-up). Salads are great; they're also boring. As for taste, well, best to form your own opinion. My omnivorous family was pleasantly surprised during trials of Beyond and its main competitor, the Impossible Burger (which switches out pea protein for soy protein and uses heme rather than beet juice to re-create the "bleed" aesthetic).

Brown also told athletes they could proceed at their own pace as "ambassadors." No hokey ads. Nothing off-brand. Basically: Eat our stuff if you want, then spread the word how you want. Veteran center JaVale McGee was an early convert to eating the product and signed on as an endorser last year. Retired center John Salley was another early adopter—he signed on for 5,000 shares and began doing what John Salley does best: talking. "The agreements we have with them are not like, they must do this or that," says Brown. "We get to know them, we can see it in their eyes, the passion, whether they have it or not. And then it's, like, any details in a contract only get in the way."

The timing proved fortunate. A new generation of consumers (and athletes) was emerging, interested in how diet affected not just their bodies but the world around them. At the same time, the days of mocking teammates for eating veggie burgers were fading. "I think that's a societal change in that there are a lot of pillars of masculinity that we're stripping down and have been for the last few years and rightfully so," says the 35-year-old Redick. "To use a phrase that I don't often use, the NBA is very much a woke league. It's at the forefront of a lot of things—training, fashion, food, diet. A lot of things that have happened in a macro way with society [are reflected in] these micro changes in the NBA."

By 2018, the company had momentum. Irving came on board. So did Oladipo and Barnes. Jordan persuaded Paul to try Beyond; in an email interview, Paul told SI he has since converted his family, including his parents, and he feels like he recovers more quickly and has more energy. Last February the company put out its first major TV ad with Irving. The spot could be selling a shoe—for 50-odd seconds we see Kyrie training, Kyrie shooting, Kyrie dribbling. At the end, beyond meat appears, alongside the company's logo of a caped steer. (Irving later wore a Beyond hat during postseason pressers.) Paul's ad is similarly low-key: We see him shooting hoops with his son, then grilling out as he talks about modeling responsible behavior. It's a long way from the days when Larry Bird and Michael Jordan went off the Grand Canyon to sell McDonald's burgers (to say nothing of the days when Vlade Divac smoked cigarettes during interviews). While some players still plug less-than-nutritious products (Irving's deal with Pepsi even led to a movie), on a larger scale, it's indicative of a new ethos in the NBA. Once upon a time, making bank was the league's aspirational currency—Republicans buy shoes too, as MJ once noted. Now, awareness and its close partner, righteousness, rule the day.

When the stock went bonkers after the IPO, players saw it as an unexpected bonus. "I don't think I could have predicted the success when I first became an investor," says Paul. Teammates and friends took notice too, suddenly hip to the vegetarian lifestyle. How do I get in? they asked the ambassadors. Says Redick with a laugh, "I told them it's a little late."

By late summer, when Beyond peaked at $239 a share, the company bore a higher valuation than Viacom, Jet Blue and Molson Coors. Those 5,000 shares Salley had? They were now theoretically worth north of a $1 million. Neither Paul nor Redick disclosed how many shares they own, but it's safe to say they did quite well in the IPO.

Meanwhile, plant-based burgers are having a moment. Chains like TGIF, Carl's Jr. and Whole Foods sell Beyond Meat, while Burger King recently rolled out its Impossible Whopper. Even KFC is testing "Beyond Fried Chicken" at an outpost in Smyrna, Ga. (McDonald's, the grand prize, remains unclaimed.) Beyond Meat counts Bill Gates, Twitter cofounder Ev Williams and Leonardo DiCaprio as backers—as well as a handful of athletes outside the NBA, like Eagles safety Malcolm Jenkins and former WNBA star Maya Moore—and Brown talks with a mixture of giddiness and reverence about the sports figures who come through his door. Cam Newton toured the facility. Mike Tyson's cannabis business moved in next door to Beyond Meat—Brown says they're now buddies. Every Wednesday, Beyond Meat's chef brings Tyson lunch.

Who knows how long the glow will last. On the day I spoke to Brown, in August, Beyond Meat had just opened a window to sell secondary shares (and taken a bit of a beating in the press for it, as companies usually wait longer). Since then, the stock has dipped to around $150, as of mid-September. Like many start-ups, Beyond is not turning a profit. CNBC talking heads deemed its market cap "beyond ridiculous." And it's worth noting that, hype aside, the fake-meat business is still roughly 1% as large as the real meat business.

Brown says he intends to keep athletes at the forefront of the company, calling them the "tip of the spear" and "the Trojan horse for our message." The players appear to be equally invested. Redick says that he hasn't sold any shares and doesn't intend to. Occasionally, he also marvels at how the very diet that once made him seem so uncool now does the opposite.