'The gift the market gives': Kevin O’Leary's golden money rule for his kids could make you a millionaire — even on a $68K salary. Are you missing out?

“Take 15% of all your paychecks, all your side hustle, any cash granny gives you, and put it in the market and just let it compound.”

Dull as it may be, O’Leary says sticking to his 15% rule will put you on track for millionaire status by the time you’re 65. And you don’t even have to earn six figures (or have a billionaire dad) to do it.

“If you make $68,000 a year, the average salary, and you do this your entire life — just 15% of your paycheck — you’ll end up a millionaire at retirement at 65.”

That’s right, you don’t need to make six figures to retire with seven in the bank. That’s thanks to the magical power of compound interest — here’s why substance matters way more than style when you’re saving for retirement.

Does compounding work?

Taking advantage of compounding requires discipline — consistently saving and investing even when markets feel volatile, or the financial news cycle is overwhelming.

But staying consistent is only part of the equation. Reaching the $1 million mark also depends on key factors, such as when you start investing and the returns your portfolio generates over time.

For example, if you start saving 15% of your income at age 25 and earn a 4% annual return, you’d only need to pull in $67,459 a year to hit the $1 million mark by 65.

Start at 40, however, and you’ll need to earn more than double — $155,086 per year — to reach the same goal with a 4% return. (And, for the record, saving over $23,000 would put you over the IRS’s annual 401(k) contribution limit.) If you can manage to get an 8% return, on the other hand, the required income drops to $83,563.

Historically, the U.S. stock market has delivered strong long-term returns. The benchmark S&P 500 has delivered an average annual return of 10.51% since 1957, though, of course, past performance is no guarantee of future results.

Still, O’Leary’s core message here is timeless: The earlier and more consistently you invest, the better your chances of growth.

“Best piece of advice I can give anybody,” he said. “Don’t buy stuff you don’t need — invest it instead.”

Here’s a look at a few simple ways you can put his advice to work in your own life.

Unlock the market’s gift

O’Leary’s advice to “put it in the market and just let it compound” echoes the philosophy of investing legend Warren Buffett.

“In my view, for most people, the best thing to do is own the S&P 500 index fund,” Buffett famously stated during Berkshire Hathaway’s annual meeting in 2020.

This approach gives investors exposure to 500 of America’s largest companies across a wide range of industries, providing instant diversification without the need for constant monitoring or active management.

Still, setting aside 15% of every paycheck may feel out of reach for many. According to the Federal Reserve Bank of St. Louis, the personal savings rate in the U.S. was just 4.1% as of Aug. 2026. This puts O’Leary’s benchmark in stark relief to what most American households are capable of saving.

The good news? You don’t have to start big.

Put your spare change to work in an index fund

Building deliberate saving habits starts with consistency. Getting used to having a certain amount of money going out every month is the first step to scaling up your investments over time. Buffett’s advice to invest in the S&P 500 is about investing regularly over 30 or 40 years, not chasing trends.

The beauty of this strategy is its accessibility — anyone, regardless of wealth, can take advantage of it.

If you’re looking to get into set-and-forget investing, you can get started with Acorns, an app that automatically invests your spare change.

How it works is simple: Just sign up and link your debit or credit cards. Then, every time you buy something, Acorns rounds up the total to the nearest dollar. This turns a morning coffee for $3.25 into a 75-cent investment in your future.

From here, that money goes into a diversified portfolio of ETFs you can tailor to your risk tolerance. Along with big names like the Vanguard S&P 500 ETF, Acorns also sets you up to invest in specific sectors of the economy through custom portfolios. This includes areas like heavy industry, energy, consumer staples and utilities.

Then, once you’re comfortable with your round-ups, you can boost your savings with recurring monthly deposits into your favorite funds. And if you sign up today with a $5 recurring deposit, Acorns will add a $20 bonus to help you begin your investment journey.

Build wealth while earning passive income

Investing in stocks is often just the first step to becoming a fully-fledged investor.

Although Buffett recommends ETFs or index funds, there are plenty of other tools that generate value in the short to medium term. From certificates of deposit to private equity offerings — there are a range of investment possibilities depending on your investing philosophy.

Beyond stocks, real estate has long been a favorite asset class for building wealth — especially among income-focused investors.

In fact, Buffett has used real estate to illustrate what a productive, income-generating asset looks like. In 2022, he said that if you offered him “1% of all the apartment houses in the country” for $25 billion, he would “write you a check.”

Why? Because, regardless of what’s happening in the broader economy, people still need a place to live, and apartments can consistently produce rent money.

And you don’t need to be a billionaire investor to get in the game.

Get started with as little as $100

Although many Americans see homeownership as the path to equity, real estate can also slot into your portfolio without the need for a massive down payment. Fractional investing, or picking up shares of property through a service, lets you get some of the benefits of real estate without having to drop 20% down on a house or apartment yourself.

Crowdfunding platforms like Arrived make it easier to get yourself a piece of that pie. Backed by investors such as Jeff Bezos, Arrived helps investors get into SEC-qualified investments in real estate, including rental homes, vacation rentals and diversified funds.

In addition to any property appreciation, Arrived’s properties can help you earn a passive income stream without any of the extra work that comes with being a landlord. No midnight maintenance calls over burst pipes required.