Energy Transfer stock can make you a millionaire, but you need to do this one thing. Can you become a millionaire by investing in Energy Transfer (ET 0.82%) stock? Absolutely. Over the long term, shares have proven a terrific investment. And given the company's unique asset base, there's a good chance this performance will be repeated in the years to come. There's only one catch: If you don't invest in this stock in a certain way, you may forfeit your chance of reaching the $1 million mark. 1 way Energy Tra ...