Berkshire Hathaway (BRK.A -0.45%) (BRK.B -0.28%) owns dozens of stocks in its $370 billion portfolio, but with the S&P 500 near an all-time high, not all of them look like attractive investment opportunities right now. However, there are two in particular that are near the top of my watch list right now. Here's what they are, and why they're worth a closer look for patient long-term investors.

An automaker with lots of potential

BYD (BYDDY 0.56%) is a China-based electric vehicle manufacturer and was a favorite of Berkshire's late vice chairman Charlie Munger. In fact, Munger went so far as to once say "I have never in my life felt more privileged to be associated with something than I feel about BYD."

The company has been around since the 1990s and was an early supplier of batteries to companies like Motorola (MSI -0.09%) before pivoting to EVs. However, producing its own electric vehicle batteries (and many other vehicle components) in-house gives it a major competitive advantage.

In the fourth quarter of 2023, BYD took the title of "world's largest EV maker" from Tesla (TSLA 0.23%) and has a 35% share of the China EV industry despite having some impressive competition. With a full lineup of EVs, the cost advantages of vertical integration, and a rapidly growing market, BYD could have a very bright future. There's also massive opportunities beyond China, as exports currently make up just 8% of sales. At roughly 19 times forward earnings estimates, BYD could still be a home run for long-term investors.

A cheap bank stock that could have major competitive advantages

Over the past couple of years, Buffett and his team have pared down their bank stock holdings considerably. However, one that is still a billion-dollar investment in Berkshire's portfolio is Capital One (COF 3.30%), the well-known regional bank that specializes in credit card lending.

For one thing, Capital One is a cheap bank stock. It trades for a 10% discount to book value (for context, Bank of America (BAC 1.32%) and JPMorgan Chase (JPM 1.55%) trade for 1.2 and 1.86 times book, respectively). Plus, the bank's business is very strong with a net interest margin of 6.69% due to the high-interest nature of credit cards, and a default rate that is well-covered by the bank's reserves.

Perhaps most significant is the pending acquisition of Discover (DFS 5.72%), which could be a positive catalyst for several reasons. For one thing, it will roughly quadruple Capital One's credit card business, as Discover has more than 300 million cardholders. Capital One also has cost advantages, including average deposit interest rates that are 138 basis points lower than Discover's, so combining both banks can lead to even wider margins. But most of all, Discover is a closed-loop card issuer, which means it owns its payment network and serves as the lender, a rare combination. Becoming owner of its own payment network will not only reduce Capital One's reliance on Visa (V -1.54%) and Mastercard (MA -0.36%), but it creates lots of possibilities to profit from high-margin interchange fees in addition to its interest income.

If you buy, use Buffett's mentality

Both of these stocks are in Berkshire's portfolio as long-term investments, and that's exactly how you should approach them if you decide to invest. Both can be volatile over shorter periods, and I have absolutely no idea what these stocks will do over the next few weeks or months. However, I'm rather confident that both will deliver strong results for patient long-term investors.