Poor Warren Buffett. I mean that in the figurative and not literal sense, of course. His beloved Berkshire Hathaway (BRK.A 1.18%) (BRK.B 1.30%) didn't perform well in 2020. When a stock delivers a gain of only 2% while the S&P 500 index jumps 16%, it wasn't a very good year.

However, I think that several of Berkshire's holdings will bring a smile to the legendary investor's face this year. Here are three Warren Buffett stocks that should especially be big winners in 2021.

Warren Buffett smiling with several people in the background

Image source: The Motley Fool.

1. Apple

Apple (AAPL -1.22%) is arguably Warren Buffett's favorite stock, trailing only Berkshire itself. Unlike Berkshire, the tech giant was sizzling hot last year with its shares skyrocketing nearly 81% higher. Don't think for a second that Apple's momentum will disappear this year.

Wedbush analyst Daniel Ives even thinks that Apple could soar as high as $200 per share. That's a premium of more than 50% to its current price. I'm not sure if the stock will attain that level in 2021, but there are several reasons to be bullish about Apple.

Perhaps most important is the outlook for iPhone sales. Newsmagazine Nikkei Asia reported in December that Apple intends to boost its iPhone production by close to 30% in the first half of 2021. This could mean that Apple's quarterly sales in the second half of the year will be especially strong.

Meanwhile, Apple's services and other products continue to enjoy solid sales momentum. The company has launched new high-end AirPods Max headphones that seem destined to become another commercial success.

Sure, Apple's valuation seems steep with shares trading at more than 30 times expected earnings. However, I don't think that will get in the way of the tech stock's prospects this year.

2. Bristol Myers Squibb

Buffett and Berkshire loaded up on pharma stocks in the third quarter of 2020. I think that several of them could perform well this year. I'm particularly bullish on Bristol Myers Squibb (BMY 1.30%).

Unlike Apple, BMS is dirt cheap right now. Its shares trade at a super-low eight times expected earnings. That bargain-basement valuation doesn't reflect the drugmaker's growth prospects at all, in my view.

BMS should be on track to win approvals for new indications for blockbuster cancer immunotherapy Opdivo. Zeposia, which has already won U.S. and European regulatory approval for treating multiple sclerosis, has a great shot at winning additional approvals for ulcerative colitis. Inrebic appears to be on the way to securing European approval for treating myelofibrosis. The company should also win U.S. approvals for cancer cell therapies ide-cel and liso-cel this year. 

While BMS awaits good news on these fronts, its current product lineup continues to rock with growing sales for blood cancer drugs Revlimid and Pomalyst, blood thinner Eliquis, and cancer immunotherapy Yervoy. I think BMS has multiple catalysts that could fire up investors this year.

3. Mastercard

Mastercard (MA 0.15%) outperformed the major market indexes in 2020 with a gain of nearly 20%. I fully expect another market-beating year in 2021 for the payment processing giant.

The COVID-19 pandemic wreaked havoc on many industries, with the travel industry hit especially hard. That was bad news for Mastercard. And it showed up in the company's Q3 results, with both revenue and earnings missing analysts' estimates. 

I see Mastercard as a great coronavirus comeback play, though. As COVID-19 vaccines become more widely available, the world could at long last turn the corner on the pandemic. That should spark an economic rebound and provide a shot in the arm (pun fully intended) for Mastercard's business.

There's one other reason why I'm optimistic about Mastercard. The company's board of directors approved a $6 billion stock buyback program in December. I expect Mastercard will be busy repurchasing its shares this year, a move that should help boost its stock price. Warren Buffett has liked Mastercard for a while. He just might love it in 2021.