At Berkshire Hathaway's latest shareholder meeting, CEO Warren Buffett announced that he would be stepping down from his position as the company's leader at the end of this year.

To put into perspective the incredible success the company has seen under Buffett's tenure, Berkshire stock was priced at roughly $18 per share when Buffett purchased a controlling stake in the business and became its chief executive in 1965. Today, a single share of Berkshire's Class A stock trades at more than $776,000.

Given that Berkshire Hathaway now has a market capitalization of more than $1.1 trillion and ranks as the world's ninth-largest company, it's likely that the investment conglomerate's most explosive days of growth are now behind it. On the other hand, Warren Buffett's company has built an incredible track record through its portfolio of high-quality investments.

With that in mind, here's a look at two companies in Berkshire's stock portfolio that could turn a $1,000 investment into much more over the long term.

Image source: The Motley Fool.

Tariffs or not, Amazon has a long growth runway

Jennifer Saibil (Amazon): Amazon (AMZN -1.01%) stock accounts for only 0.7% of the Berkshire Hathaway equity portfolio, but it's been a lucrative addition, gaining around 187% since Berkshire first purchased the stock in 2019. Amazon stock is down 6% this year as investors worry about the impact of tariffs on its e-commerce business, but there's plenty of opportunity for Amazon to grow and create shareholder value, and now is an excellent time to take a position.

Before determining how tariffs might impact Amazon, it's important to understand just how much of a lead Amazon has in e-commerce. It controls nearly 40% of all U.S. e-commerce, and as it constantly improves its delivery times and product assortment, its Prime members rely on it for more and more of their essentials and other purchases.

On the company's most recent earnings call, CEO Andy Jassy discussed how the company is viewing the tariff situation. He made four separate points. Jassy explained that:

1. Many U.S. retailers buy from resellers who buy goods from China, so customers buying on Amazon directly from Chinese sellers will still get a lower price.
2. People are buying everyday essentials from Amazon, like groceries, where Amazon has a $100 billion business, and these are less susceptible to being curtailed.
3. The company offers a huge assortment of products, which is beneficial because customers can easily switch to other products without leaving Amazon.
4. When there's uncertainty, shoppers tend to buy from companies they trust.

But that's just one part of the whole, even though it's Amazon's core segment. Amazon Web Services (AWS) is a cloud services business that has less exposure to tariffs, and it's also Amazon's main source of operating income, accounting for 63% of the total in the first quarter. It's also where the exciting things are happening, since that's where it houses its generative artificial intelligence (AI) business.

Jassy has mentioned many times that he expects companies to shift tech spend to the cloud, and generative AI is going to become another essential component of every app. Amazon is poised to benefit from this shift in a massive way. Advertising, which is the company's fastest-growing segment, is largely insulated from tariffs as well, and so is streaming.

In other words, Amazon is well-positioned to withstand the impact of tariffs, and it has a huge growth runway.

This Buffett-backed beverage giant could thrive for another 100 years

Keith Noonan (Coca-Cola): Warren Buffett is known for a being a big fan of Coca-Cola's (KO -0.34%) namesake soda -- so much so that he drinks around five cans of the beverage a day. Buffett is also a big fan of the company as an investment and has made the stock one of the pillars of Berkshire's portfolio. As of this writing, Coca-Cola accounts for 10% of Berkshire's total public stock holdings. Berkshire also stands as Coke's single largest shareholder.

Founded in 1892 and taken public in 1919, the company has managed to deliver reliable earnings growth through shifting market conditions -- and it's been a huge winner for Berkshire Hathaway. Buffett has famously said that he would never sell a share of Coca-Cola stock, and he reiterated that statement at the company's most recent shareholder meeting.

Trading at roughly 24 times this year's expected earnings, Coca-Cola may not look particularly cheap compared to its sales momentum and earnings growth. On the other hand, stable and dependable industry leaders naturally command somewhat of a valuation premium, and Coke has repeatedly shown that it has what it takes to be a long-term winner. The business is relatively mature at this point and having some difficulty growing sales, but ongoing efficiency improvements are still pushing profits higher.

Coke stock also offers a solid dividend yield of 2.8%, and it's virtually certain that investors who buy the stock at today's prices will enjoy higher yields over time. In February, Coke raised its dividend roughly 5% -- and the move marked the 63rd straight year that the company has increased its dividend payout per share. Only eight stocks in the entire market have a longer history of annual payout growth.

So while Coca-Cola may not be the flashiest or most exciting business, it's an extremely reliable one that offers highly dependable passive income generation.