Warrants are derivative securities that allow holders the right, but not obligation, to buy a company's stock at a fixed exercise price at some point in the future, and act in many ways like call options.
Manziel joins a star-studded lineup of endorsers under the MusclePharm umbrella, including San Francisco 49ers quarterback Colin Kaepernick, Indianapolis Colts safety LaRon Landry and professional golfer Tiger Woods, among others.
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Earlier this year, Woods signed his endorsement deal with the company, which includes use of a logo golf bag during all professional play in return for nearly 447,000 shares of restricted stock, worth around $5 million at the time the award was granted.
The use of stock-based compensation is getting more and more traction as a part of endorsement deals. The practice allows companies to forego paying out cash, in exchange for an equity interest. Meanwhile, recipients of the awards give up cash payments upfront and, in return, gain the possibility of richer rewards down the line if the company becomes more successful.
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Perhaps Johnny Football wants to see if he can craft his own stock market success story, much like rapper 50 Cent did when he made a reported $100 million after Coca-Cola purchased Vitaminwater-maker Glaceau for $4.1 billion in 2007. 50 Cent had negotiated an equity stake in Glaceau as part of an endorsement deal.
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While Manziel's deal may not ever lead to that kind of payout, it might be wise for him to keep an eye on the ticker and see whether or not MSLP shares trade above $11.90 in the next couple of years.
—By CNBC's Dominic Chu