We've all heard the old saying, "It takes money to make money." It's no surprise, therefore, to learn that super-wealthy individuals often make a lot of money.

Few people in the world are wealthier than Warren Buffett. And few will add to their wealth as much as the Oracle of Omaha will in 2023. Buffett is on track to make $13.6 billion this year. Here's how he'll likely do it.

Buffett's gold mine

Most of Buffett's fortune is in Berkshire Hathaway (BRK.A -0.76%) (BRK.B -0.69%) stock. Berkshire has been a gold mine for Buffett through the years, delivering a gain of close to 37,875x since 1964.

Berkshire has continued to be golden for Buffett in 2023. The share price of the giant conglomerate is up more than 14%. That's enough to add roughly $13.6 billion to Buffett's net worth.

Where did this figure come from? Berkshire's market cap is on pace to increase by around $87 billion this year. Buffett owns 15.6% of the aggregate economic interest of Berkshire's class A and class B shares. His portion of the increase in Berkshire Hathaway's valuation, therefore, is worth roughly $13.6 billion.

Of course, Berkshire's share price could decline over the next few weeks and result in Buffett making less money. However, if we experience a Santa Claus rally, which often takes place at the end of the year, the legendary investor could end up with an even bigger gain.

What made Berkshire Hathaway's stock rise this year?

I promised to explain exactly how Buffett will likely make $13.6 billion in 2023. To do that, I think we need to explore what made Berkshire Hathaway's stock rise this year. What makes any stock go up? As is the case with other products, the laws of supply and demand are the primary drivers of price increases.

The supply of Berkshire Hathaway stock has decreased in 2023 thanks to stock buybacks. Berkshire repurchased $7 billion of its Class A and Class B shares in the first nine months of the year. This isn't a major factor behind the stock's jump in 2023, though, as the buybacks represent only 1% of Berkshire's market cap at the beginning of the year.

We can therefore logically conclude that the demand for Berkshire Hathaway stock has increased quite a bit. Why? Arguably, the biggest reason is that investor sentiment has improved with the overall market rising.

This is especially important for Berkshire because it's invested heavily in other publicly traded companies. During the first three quarters of 2023, Berkshire's investment gains of $38 billion made up more than half of its earnings before income taxes.

One stock especially stands out as a major driver of those hefty investment gains. Nearly 49% of Berkshire's portfolio is invested in Apple (AAPL -0.35%). So far in 2023, Apple's share price has soared close to 50%.

Berkshire's stock performance this year is also due in part to the company's underlying business performance. The conglomerate's insurance business has done well, with premiums rising 13.6% year over year in the first three quarters of 2023 to $61.7 billion. Berkshire's utility and energy businesses have performed even better during the period, with operating revenue more than quadrupling to $53.5 billion.

How much will Buffett make in 2024?

Whether or not Buffett's net worth increases in 2024 -- and by how much -- will again depend on how Berkshire Hathaway stock performs. What happens with Berkshire stock will again hinge heavily on Apple and the overall stock market.

The good news for Buffett is that the stock market tends to perform pretty well during U.S. presidential election years. If the U.S. economy continues to roll along, Berkshire's underlying businesses should also grow.

There's no way to know for sure how much Buffett will make next year. However, it won't be surprising if he adds several more billions of dollars to his fortune.