SHARK TANK – Mark Cuban is a “Shark” on ABC’s “Shark Tank.” (ABC/Patrick Ecclesine)

Legend has it that when Mark Cuban arrived in Dallas, he had less than $100. More than 80 businesses, “Shark Tank” and three phones later, Cuban is a wealth of financial tips. And yes, he does turn off all three of his phones when he’s sleeping. At least, he thinks they’re off.

What’s your No.1 tip on diversifying a portfolio?

Don’t. Diversification suggests that you have the knowledge base to invest in a cross section of stocks or bonds or XYZ. It’s hard enough to find one stock that will work, let alone a full portfolio that hedges your risk and offers sufficient upside.

How do you make the best of your money in Preston Hollow?

I enjoy it. I have a great home with a yard for the kids to play on. I go to lunch at True Food Kitchen, eat poke, get my hair done and more — all in Preston Hollow. Everything is convenient.

When’s the best time to start a business?

When you’re young and don’t have anything to lose. After that, it’s when you know you are prepared and understand what you are doing. If you aren’t sure, you aren’t ready.

What are the top three books you read in 2018?

“Citizen Cohn,” the book about Donald Trump’s mentor Roy Cohn. It’s fascinating how similar they are. “That’s What She Said,” by Joanne Lipman, a book that explores diversity and gender roles and how men can better work with women. “The Once and Future Worker,” a book that challenges the notion of the country chasing GDP growth as opposed to increasing production and work opportunities that are more fulfilling and further reaching.

What’s been your favorite business venture thus far? 

Alyssa’s Healthy Cookies. I helped the founder go from being near bankruptcy to having an incredible product that is growing sales and profits monthly.

If someone wanted to be on “Shark Tank,” what shouldn’t they do?

Talk about themselves more than the business. There is a great business rule that says, “The longer the backstory, the worse the business.”

What’s the best business tip someone gave you?

Sales cures all. No business has ever succeeded without sales.

What’s it like shooting on the Mavs’ court on game day?

A dream come true. For me, hearing the ball go through the net is the ultimate stress release. And doing it on an NBA court is an incredible feeling.