When Fantex Holdings first announced its intention to offer athlete "tracking stocks" the concept was met with a lot of skepticism in the business press. That was in 2013, and in April 2014, the brokerage brought its first athlete stock public: Vernon Davis, then a tight end for the San Francisco 49ers. The skepticism hasn't entirely faded, but in the 18 months since, the company has brought five more football player stocks to market. And in September it signed a contract with Los Angeles Angels pitcher Andrew Heaney, its first athlete outside of football.

Now it's getting into golf. Fantex has signed a deal with 26-year-old golfer Scott Langley, Yahoo Finance is first to report.

Langley is best known for finishing 16th at the 2010 U.S. Open, where he tied for the best amateur score. He is also the first alum of The First Tee, a youth golf program started by the World Golf Foundation in 1997, to actually make it to the PGA Tour.

Langley is far from a household name. But he's in the perfect sweet spot for Fantex, which makes sense for a young athlete who isn't yet a mega-star—the athlete gets an upfront fee that you can think of as an insurance policy against future earnings. If he were to get injured or perform poorly, he still gets his money. Take Heaney, for example. "The up-front, lump sum of cash," French says, "allows him to actually approach his recovery as a pitcher like a veteran who already has his major contract." An established star like Tom Brady or Peyton Manning wouldn't sign this kind of deal because they don't need the fee enough to promise anyone a portion of their future earnings, which are likely to be high.

The athletes that have signed on thus far vary in terms of their fame and brand, but none are mega-stars. They are at a point in their careers where an upfront fee has great appeal. The full Fantex roster now looks like this: Davis (now with the Denver Broncos), Alshon Jeffery (Chicago Bears), Mohamed Sanu (Cincinnati Bengals), EJ Manuel (Buffalo Bills), Jack Mewhort (Indianapolis Colts), and Michael Brockers (St. Louis Rams, now the L.A. Rams) have all gone public. The remaining five that have signed are Kendall Wright (Tennessee Titans), Ryan Shazier (Pittsburgh Steelers), Terrance Williams (Dallas Cowboys), baseball pitcher Heaney, and now golfer Langley.

How does Fantex actually work? The company pays every athlete it signs a one-time, upfront lump sum in return for a percentage of the athlete's future brand income—all future income tied to the athlete's brand, whether it's from the sport or from business outside of it. (That includes, for example, money from endorsement deals, fast-food franchising, speaking engagements, TV appearances and more.) In Langley's case, Fantex is paying Langley $3.06 million in return for 15% of his future brand income. Fantex raises that fee from the IPO process; if it fails to sell enough shares of the athlete in the offering, it can't pay him. It has successly brought all six of its attempted offerings public, but it had to cancel the offering of Arian Foster, who was planned to be its first stock. Foster is a bigger star than any of the athletes Fantex has brought public, but he was sidelined by a back injury shortly after Fantex announced the deal.

As for the investors, what you're actually buying is a tracking stock—more like a share of Fantex itself—that should, in theory, rise and fall based on the success of the athlete. In practice, there hasn't been significant liquidity with the six athletes Fantex offers: none of them is currently trading very far from the $10 IPO price, and they don't fluctuate enough yet to be particularly exciting.

If you had bought $1,000 worth of Alshon Jeffery when it debuted at $10 in November 2014, today you would have $1,100. Jack Mewhort's stock has risen the most, but only to $12. EJ Manuel shares have fallen to $7 after he only played in seven games for the Bills this season. None of the securities moves dramatically from day to day.

Fantex CEO Buck French remains confident that athlete tracking stocks can become "a new asset class" for smart investors looking to diversify their portfolio.

To that end, Fantex has also announced its first "basket" of athlete stocks: a portfolio containing all 10 of the athletes it has signed (minus Langley, who won't go public for many months) with each one weighted differently. UBS will serve as the underwriter and Fantex is applying to debut the basket on the New York Stock Exchange under the ticker FXSP. Investors will be able to buy shares of the basket directly from the NYSE, like any typical corporate stock, whereas the individual athlete stocks must be bought and traded on Fantex's web site.

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