The Gronkowski family loves to compete.
All five brothers have had successful careers in professional sports: Rob, Chris, Glenn and Dan played in the NFL, while Gordon played Major League Baseball. Rob, 28, famously nicknamed "The Gronk," is playing in the Super Bowl on Sunday with the New England Patriots.
But these days Chris Gronkowski, 30, is focusing on business, not football. In October, Chris, who most recently played for the Denver Broncos, pitched his company, Ice Shaker, on ABC's "Shark Tank" and brought his siblings along for support. But this time it wasn't the brothers competing — it was the sharks.
All five "Shark Tank" investors, including guest judge, Alex Rodriguez, clamored for a piece of the business, which sells insulated bottles that are an upscale version of plastic cups used to mix up protein shakes.
Rodriguez landed the deal in partnership with Mark Cuban, and the pair invested a combined $150,000 for a 15 percent stake in the business.
For Rodriguez, investing in Chris has been a success.
"He's been terrific," Rodriguez tells CNBC Make It. "He's under promised and he's over delivered. Our sales have done incredibly well."