Warren Buffett and the rest of Berkshire Hathaway's (NYSE:BRK.A)(NYSE:BRK.B) investing team typically don't discuss the stocks they buy and sell, so we have to rely on the quarterly glimpses of the portfolio we get from Berkshire's SEC filings.

Berkshire just posted its most recent 13-F filing, which shows a snapshot of the stocks it held as of Dec. 31, 2020. Berkshire added a few new positions, built some of its existing ones, and sold some stocks as well. Here's a complete rundown of all of the moves Berkshire made.

Warren Buffett smiling.

Image source: The Motley Fool.

4 new stocks in Berkshire's portfolio

Buffett and his team added a few stocks during the fourth quarter:

Company (Symbol)

Shares Bought

Market Value

Verizon (NYSE:VZ)

146,716,496

$8.62 billion

Chevron (NYSE:CVX)

48,498,965

$4.10 billion

Marsh & McLennan (NYSE:MMC)

4,267,825

$499 million

EW Scripps (NASDAQ:SSP)

23,076,923

$364 million

Data source: Berkshire Hathaway 13-F. Market values as of 2/17/21.

We already knew about the Scripps investment, which technically took place in January, but since it's a new position to the portfolio, it's still worth noting.

The Verizon and Chevron buys were the two biggest stories of the quarter by far. It's unusual for Buffett to buy such large positions right away, so it looks like the Oracle of Omaha is quite confident in these choices.

However, neither decision is too surprising. Verizon, in particular, is a rock-solid income stock trading for a reasonable valuation and could have quite a bit of upside potential during the wide-scale rollout of 5G technology in the coming years.

6 stocks Berkshire bought more of

In addition to the new purchases, Berkshire added to some of its existing investments. There are no surprises here. Buffett began building positions in several pharmaceutical stocks in the third quarter, as well as in T-Mobile U.S. These moves are just continuations of those purchases.

Company (Symbol)

Shares Bought

Market Value of New Shares

AbbVie (NYSE:ABBV)

4,268,766

$455 million

Merck (NYSE:MRK)

6,294,333

$477 million

Bristol Myers Squibb (NYSE:BMY)

3,364,822

$204 million

Kroger (NYSE:KR)

8,555,578

$291 million

RH (NYSE:RH)

24,200

$11 million

T-Mobile U.S. (NASDAQ:TMUS)

2,824,844

$343 million

Data source: Berkshire Hathaway 13-F. Market values as of 2/17/21.

6 stocks Berkshire reduced

While Buffett says that his "favorite holding period is forever," Berkshire sells stocks quite regularly. In the fourth quarter, we learned that Berkshire reduced six of its stock positions.

Company (Symbol)

Shares Sold

Market Value of Shares Sold

Apple (NASDAQ:AAPL)

57,160,000

$7.44 billion

U.S. Bancorp (NYSE:USB)

823,834

$40 million

General Motors (NYSE:GM)

7,500,000

$397 million

Wells Fargo (NYSE:WFC)

74,956,573

$2.76 billion

Suncor Energy (NYSE:SU)

5,352,318

$100 million

Liberty Latin America (NASDAQ:LILAK)

146,177

$1.7 million

Data source: Berkshire Hathaway 13-F. Market values as of 2/17/21.

The two largest reductions by far were Apple and Wells Fargo, but neither was a huge shock. Apple has been an incredibly successful investment for Berkshire, but with the stake representing over one-fifth of Berkshire's entire market cap, it was due for a trim. Wells Fargo is a stock Buffett has been reducing for some time.

5 stock positions Berkshire exited completely

Berkshire has been unloading most of its bank stocks that aren't called Bank of America (NYSE:BAC) in recent quarters, and the fourth quarter was no exception. In fact, Berkshire completely sold out of five stock positions in the quarter, three of which were banks.

Company (Symbol)

Shares Sold

Market Value of Shares Sold

PNC Financial (NYSE:PNC)

1,919,827

$321 million

JPMorgan Chase (NYSE:JPM)

967,267

$140 million

M&T Bank (NYSE:MTB)

2,919,613

$431 million

Barrick Gold (NYSE:GOLD)

12,000,000

$250 million

Pfizer (NYSE:PFE)

3,912,216

$137 million

Data source: Berkshire Hathaway 13-F. Market values as of 2/17/21.

What it all means to you

We don't know why Buffett and his team decided to buy or sell these stocks. We can speculate, but Buffett is notoriously tight-lipped when it comes to moves in Berkshire's stock portfolio.

Keep in mind that this is a snapshot of Berkshire's portfolio at the end of 2020. With the exception of E.W. Scripps, which was reported in January, we have no idea what Berkshire has done in the past month and a half.

Investors should take this information with a big grain of salt. It's generally not a great idea to buy or sell any stock just because a billionaire did, even if that billionaire is Warren Buffett. There's nothing wrong with using this information as a starting point for your own investment research, but it's still important to do your due diligence.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.