There's nothing average about former basketball star turned angel investor Shaquille O'Neal. So when he says he "probably quadrupled" his net worth using a simple investing strategy, it's worth paying attention to.

In a recent interview with the Wall Street Journal , O'Neal said: "I heard Jeff Bezos say one time [that] he makes his investments based on if it's going to change people's lives," and "once I started doing that strategy, I think I probably quadrupled what I'm worth."

That adds up. During his 19-year career in the NBA, O'Neal racked up around $300 million that he's used to invest in everything from early stakes in Google and Apple to an empire of Vegas nightclubs and fast food franchises like Five Guys, Auntie Anne's and Papa John's, according to Money .

Since retiring from the league in 2011, O'Neal has been an outlier in the trend of professional athletes that struggle with finances post-retirement . O'Neal took his earnings and reinvested them according to what he liked, he told the Wall Street Journal.

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"If something comes across my desk and I don't believe in it, I don't even look at it," O'Neal told the Wall Street Journal. "Whenever I do business, it's not about the money."

He said Google has been his best investment by far, but he most enjoys his investment in the Krispy Kreme donut chain.

"I like donuts...Krispy Kreme is a fabulous donut. I was introduced to it in college and have been in love with it ever since," O'Neal told the Wall Street Journal.

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