Most pro football fans already find themselves personally invested in the fortunes of their teams and favorite players. Now they can get a return on that investment.

Fantex, a brokerage based in San Francisco, offered 421,000 shares of San Francisco 49ers' star tight end Vernon Davis to the public Monday, making him the first-ever publicly traded athlete. Davis' "initial public offering" was priced at $10 per share, and at mid-afternoon was up 10% on volume of 101 shares.