Last week, I was honored to have the incredible opportunity to interview Tony Robbins about his new book, Unshakeable: Your Financial Freedom Playbook. You can watch the full interview on YouTube, which, at the time of publishing this article, already had more than 50,000 views.

Since Robbins is already a No. 1 New York Times best-selling author from his first book, Money: Master the Game (which I covered in my previous article "7 Simple Steps to Financial Freedom"), my first question was why he published a second book on the topic of financial and money mastery.

"That's a great question, because I wrote 670 pages for Money: Master the Game and I think you know that I don't like writing," Robbins says. "But I was so obsessed, because after 2008 seeing everybody losing homes and half of their net worth and seeing nothing be done about it." He wanted to give people a step-by-step guide to money mastery. And deliver he did.

Robbins is the master of identifying patterns. In Money: Master the Game, he interviewed 50 of the brightest minds in finance and did a deep dive on all the tools and techniques that some of the richest men in the world used to establish and grow their wealth. Now, in Unshakeable, Robbins goes one step further by simplifying what you need to know in what he calls the Core Four.

"What I've found over almost four decades of studying success," says Robbins, "is that the most successful people in any field aren't just lucky. They have a different set of beliefs. They have a different strategy." And in studying the masters, Robbins discovered there are four principles that "nearly all great investors use to guide them in making investment decisions." He calls these principles the Core Four. "In short, the Core Four should be at the very heart of your investment playbook," says Robbins.

Core Principle 1: Don't Lose

When it comes to investing, most of us make the mistake of focusing on the wrong things. We ask, "How can I make money?" instead of protecting ourselves against losing money. In his book, Robbins points out that if you lose 50 percent of your investment, you actually need to make 100 percent to get back to where you started before the loss.

Robbins cites many incredible examples of this core principle, including Warren Buffett's famous first two rules of investing: "Rule number one: Never lose money. Rule number two: Never forget rule number one." He also talks about Ray Dalio, who has produced $45 billion in profits for his investors, who told Robbins, "What I realized is nobody knows and nobody ever will. So I have to design an asset allocation that, even if I'm wrong, I'll still be OK." So when the billionaires are obsessed with not losing, then we need to, as Robbins puts it, "design an asset allocation that ensures we'll 'still be OK' even when we're wrong."

Core Principle 2: Asymmetric Risk/Reward

This is where so many of us get tripped up. Because we tend to focus on how we can make money (instead of not lose money) when investing, we fall into the trap of risking $1 to earn 8 cents. Think about your current investments. If you're like most people, you're invested in mutual funds that charge high fees, try to beat the market and risk every dollar you invest to make a target 8 percent return.

"But the best investors don't fall for the high-risk, high-return myth," says Robbins. "Instead, they hunt for investment opportunities that offer what they call asymmetric risk/reward: a fancy way of saying that the rewards should vastly outweigh the risks. In other words, these winning investors always seek to risk as little as possible to make as much as possible. That's the investor's equivalent of nirvana."

In this core principle, Robbins talks about Sir Richard Branson, who, before he launched Virgin Airlines, worked with the airline manufacturers to agree to let him give back the planes should his airline fail. That way, he got maximum upside should his new airline succeed, while minimizing his risk if the venture failed. You see, Branson may take all kinds of risks in his personal life, but when it comes to his business, he is a genius at asymmetric risk/reward.

Core Principle 3: Tax Efficiency

When it comes to the most successful investors, they are really smart about taxes. "They know that it's not what they earn that counts," says Robbins. "It's what they keep. That's real money, which they can spend, reinvest, or give away to improve the lives of others."

If you're considered a "high earner" by the IRS, you could be paying an ordinary income tax rate of as much as 50 percent when you combine federal and state taxes. It's really hard to keep your investments when you're paying as much as half to the government. That's why it's critical to focus on your after-tax returns and to take advantage of tax-efficient investment strategies (outlined in both of Tony Robbins's books, Money: Master the Game and Unshakeable). You also need to maximize your tax-advantaged investment vehicles such as your company's 401(k), IRAs, college-savings programs, and other retirement programs.

Core Principle 4: Diversification

Most everyone knows the importance of diversification when it comes to investing, but Robbins breaks diversification down into four subgroups:

Diversify across different asset classes.
Diversify within asset classes
Diversify across markets, countries, and currencies around the world
Diversify across time

And that's the Core Four. I'd love to say this is all you need to know, but that's not the case. Robbins goes to great lengths to simplify everything you need to know and do to follow your own financial freedom playbook. So I urge you to pick up your copy of Unshakeable. And I was told, in my interview with Robbins, that when you preorder now, you also get a free gift. Just like in Money: Master the Game, all of the proceeds of Unshakeable go to Feeding America, so you can join Robbins on his mission to deliver one billion meals in the next eight years.