At the end of June, Putnam Investment Management was Bear's largest institutional shareholder with 7.03 million, or 6%, of Bear's outstanding shares.
Lewis, who prefers to keep a low profile, wouldn't comment on his stake in Bear Stearns when CNBC spoke to him on Monday. But the move speaks to the kind of investor he is -- often seeing value where others see risk.
Born in London and now in his seventies, Lewis made his billions in the volatile world of currency trading, making big bets that paid off. His private equity firm, the Tavistock Group, has a stake in a European soccer club, a car company and is the official marketer of sportswear maker Puma in Mexico.
The group also has invested heavily in high-end golf course communities, and holds the annual Tavistock Cup in Florida, attracting some of the biggest names in the sport, including Tiger Woods and Ernie Els, both of whom call his communities home.
The two pros are partnering with Lewis to develop a new resort-style community, called Albany, in the Bahamas.
Woods explained why he made the deal. “The only reason I'm doing it is because of my relationship with Joe,” Tiger said. “Joe Lewis has been one of my good friends.”
Lewis inspires such faith, in part, because he's so good at making investments pay off. He also is no stranger to philanthropy, routinely giving millions away.
Bear Stearns' shares are down 35 percent this year, hammered by the collapse of two hedge funds and its heavy reliance on mortgage-related revenue amid a meltdown in the subprime lending industry.
Lewis-controlled entities named Aquarian, Cambria, Darcin, Mandarin and Nivon bought large blocks of Bear Stearns shares in August and September, the SEC filing shows. The last reported purchase was a block of 400,000 shares on Sept. 4.