SAN FRANCISCO (AP) — An unusual startup trying to sell stock in star athletes is now hoping San Francisco 49er tight end Vernon Davis will prove the concept is a winner.

Documents filed Thursday by Fantex Inc. proposed selling 421,000 shares at $10 apiece to investors who want a piece of Davis’ future earnings.

The IPO funds will be used to pay Davis a $4 million fee in exchange for 10 percent cut of his future income tied to football.

The 29-year-old Davis could be paid up to $16.9 million on the remainder of his current contract with the 49ers.

Fantex, based in San Francisco, filed plans last month to sell stock in the Houston Texans’ running back Arian Foster. That deal was called off last week after Foster suffered a season-ending injury.