Tony Robbins, the performance coach best known for his high-energy seminars, has over the past few years dedicated himself to spreading personal-finance literacy.

He’s conducted interviews with 50 of the top investors in the US, including Bridgewater Associates founder Ray Dalio, Vanguard founder Jack Bogle, and JPMorgan Asset Management CEO Mary Callahan Erdoes.

Robbins’ project has always been intended for a wide, general audience, but he found that millennials who entered the workforce during or around the recession, often with a heap of student loans, especially needed some guidance.

Robbins recently came by Business Insider’s New York office for a Facebook Live question-and-answer session in which he discussed his latest book based on these interviews, “Unshakeable,” a much slimmer version of his 2014 book, “Money: Master the Game,” with additional insights from Peter Mallouk, who was rated the No. 1 wealth adviser in the US by Barron’s three times and who brought Robbins into his firm Creative Planning in 2016.

Many viewers were interested in how someone with little or no assets could get a strong start to their finances, even if they happened to be saddled with debt. Robbins noted that before you begin to invest, you need to establish an emergency savings account with enough cash to cover a minimum of three months of expenses. This will give you a safety net for the life-shaking events that often come out of nowhere – like getting laid off or suffering an injury with a large hospital bill.

Here’s what Robbins said:

1. Make use of compounding interest as early as possible

After he was asked how a millennial with little money could start investing, Robbins mentioned his interview with renowned economist Burton Malkiel. “I said, ‘You’ve been around a long time: What’s the biggest mistake that people are making today?'” Robbins said. “And he said, ‘Tony, it’s that they do not tap into the power of compounding interest.’ We all know about it intellectually, but it is a force that will make you wealthy.”

Compounding interest is the interest that accrues on top of the principal and interest from previous periods.

In “Unshakeable,” Robbins uses a hypothetical example to illustrate the mathematics. There are two friends who are the same age, Joe and Bob. Joe begins investing $300 in the stock market every month from age 19 to 27, saving a total of $28,000. Bob does the same, but from age 27 to 65, for a total of $140,000. The stock market in this example grows 10% annually, a number chosen for its simplicity. By age 65, Joe has $1,863,287 and Bob has $1,589,733.

Again, that’s an example using simple math just to show that even though Joe invested for less time than Bob, he made more money because he started earlier. Warren Buffett, for example, says you should expect a 6% to 7% average return from the stock market in the long term (10 or more years).

The market can be erratic in the short term, but over the past 200 years it has grown on a macro scale. Buffett, in his latest letter to Berkshire Hathaway shareholders, announced that he was on his way this year to winning the $1 million bet he made in 2007: that his investment in an S&P 500 index fund would outperform five hedge funds over a decade.

2. Diversify

“You have to diversify,” Robbins said. “You can’t put all of it in one place.”

In “Unshakeable,” Mallouk writes that he recommends to his clients a mix of stocks, bonds, and alternative investments like real-estate investment trusts. For the average investor, it’s best to work with a fiduciary to determine the best portfolio for your needs.

A good place to start on your own, however, is investing in an index fund, which allocates money across companies in an index, essentially giving you representative ownership of that market – which, again, historically grows over time regardless of short-term performance.

3. Automate your investments

Finally, Robbins said, it’s necessary to make investing for your future a habit you don’t have to think about.

Make use of the 401(k) match your company offers, if it does, and determine a percentage of your paychecks (5%, 10%, 15% – whatever works for you at that point in your life) that will automatically go to your investments every month.

Robbins said that he understood the initial steps required an adjustment in a person’s mental and physical relationship to money but that it was very much worth the effort.

“It’s hard to do, but if you start to automate it, and you do it regularly, oh, my God, you will have financial freedom that most people never have,” he said. “More importantly … [you’ll have] peace of mind, you’ll have inner strength. You’ll know that you’ve mastered this area of your life. And it’s not complex.”

You can watch the full Facebook Live Q&A with Robbins below.