InvestIdeas

His first rule was "never get too concentrated," warning against putting too much money into a single investment.

He also advised to "keep debt under control" and "stay liquid."

O'Leary's fourth rule was to "protect the principal and live off the cash flow," emphasizing the importance of preserving invested capital while using investment income to support expenses.

His final rule was direct: "never own an investment that doesn't pay you."

"Wealth is not just about how much you own."

"It is about protecting your capital, staying flexible and making sure your money keeps working for you," he added.