When Berkshire Hathaway (NYSE: BRK.A)(NYSE: BRK.B) released its third-quarter earnings report, we learned that Warren Buffett and his team had quite an active quarter in the stock market. The cost basis of Berkshire's massive stock portfolio increased by about $9.6 billion, and it appeared that there had been some selling in the portfolio as well. Well, on Monday afternoon we got a glimpse of what the Oracle of Omaha has been buying and selling with the release of Berkshire's Form 13F, which institutional money managers are required to file 45 days after the end of each quarter. Here's a breakdown of the recent moves investors should know about. Image source: The Motley Fool. Here's what Buffett and his stock pickers have been buying We already knew about a couple stock purchases Buffett and his lieutenants made -- specifically that they spent more than $2 billion adding to their already large position in Bank of America and invested $720 million in Snowflake's recent IPO. But the company's quarterly report indicated that this was just a tiny fraction of Berkshire's stock buying activity. With that in mind, here's a rundown of what stocks Berkshire Hathaway added to its portfolio in the third quarter: Company (Symbol) Shares Bought Market Value of New Shares (rounded) New Position? Bank of America (NYSE: BAC) 85,092,006 $2.35 billion No Snowflake (NYSE: SNOW) 6,125,376 $1.44 billion Yes General Motors (NYSE: GM) 5,319,000 $224 million No AbbVie (NYSE: ABBV) 21,264,316 $1.86 billion Yes Merck (NYSE: MRK) 22,403,102 $1.86 billion Yes Bristol Myers (NYSE: BMY) 29,971,194 $1.81 billion Yes Kroger (NYSE: KR) 3,038,360 $99 million No T-Mobile US (NASDAQ: TMUS) 2,413,156 $318 million Yes Pfizer (NYSE: PFE) 3,711,780 $136 million Yes Liberty Latin America Class K (NASDAQ: LILAK) 66,567 $780,000 No Data source: Berkshire Hathaway SEC filings. Market value as of 11/16/2020. The biggest story on the buying side was the addition of not one but four big pharma stocks. Buffett (or one of his stock pickers) initiated stakes worth nearly $6 billion altogether, including three large and nearly equal-sized positions in AbbVie, Merck, and Bristol Myers. Aside from this, the initiation of a new position in T-Mobile US is also noteworthy, although a $318 million investment is rather small by Berkshire's standards. This isn't totally a surprise -- Berkshire reportedly considered a large investment in Sprint (now a part of T-Mobile) in 2017. In addition to the stocks in the chart above, it's also worth noting that Berkshire also repurchased more than $9 billion of its own stock during the quarter. Berkshire also hit the sell button on a few stocks While Berkshire was an active buyer of stocks in the third quarter, the quarterly report indicated that Buffett and company may have continued to pare back some of their other bank investments and that they may have taken some profits in their largest holding, Apple. Here are the particulars of these moves. Company (Symbol) Shares Sold Market Value of Shares Sold Did Berkshire Sell All Shares? Apple (NASDAQ: AAPL) 36,326,710 $4.37 billion No DaVita (NYSE: DVA) 2,000,000 $226 million No Wells Fargo (NYSE: WFC) 110,202,265 $2.74 billion No Axalta Coating Systems (NYSE: AXTA) 650,000 $18.4 million No Liberty Global (NASDAQ: LBTYA) 1,300,000 $29.3 million No Barrick Gold (NYSE: GOLD) 8,918,701 $229 million No M&T Bancorp (NYSE: MTB) 1,616,561 $205 million No PNC Financial (NYSE: PNC) 3,430,759 $433 million No JPMorgan Chase (NYSE: JPM) 21,241,160 $2.50 billion No, but sold 95% of stake Liberty Latin America (NASDAQ: LILA) 160,478 $1.9 million No Costco (NASDAQ: COST) 4,333,363 $1.69 billion Yes Data source: Berkshire Hathaway SEC filings. Market value as of 11/13/2020. We knew Berkshire sold some Apple, and Berkshire's SEC filing confirmed it. The same goes for bank stocks, with the Wells Fargo, JPMorgan Chase, and other bank-stock sales adding up to nearly $6 billion. On the selling side, the biggest surprise is definitely the sale of the company's entire Costco stake. This likely resulted in a big profit for Berkshire, as Costco stock is trading for about $380 per share right now, roughly 10 times what Berkshire likely paid for it. Also surprising is that Berkshire sold more than 40% of its Barrick Gold investment, which was just initiated during the second quarter. An active quarter that shows Berkshire is ready to put money to work Between Berkshire's massive buybacks, this quarter's wave of other stock purchases, and some other investments Berkshire has made recently, it is crystal clear that Warren Buffett is now in capital deployment mode. And with about $140 billion in cash and equivalents still on the balance sheet, this could be just the beginning. 10 stocks we like better than Berkshire HathawayWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Berkshire Hathaway wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of October 20, 2020 Matthew Frankel, CFP owns shares of Apple, Bank of America, Berkshire Hathaway (B shares), General Motors, and Wells Fargo and has the following options: short January 2021 $23 puts on Bank of America and short November 2020 $22.5 puts on Wells Fargo. The Motley Fool owns shares of and recommends Apple, Berkshire Hathaway (B shares), Bristol Myers Squibb, Costco Wholesale, and Snowflake Inc. The Motley Fool recommends T-Mobile US and recommends the following options: long January 2021 $200 calls on Berkshire Hathaway (B shares), short January 2021 $200 puts on Berkshire Hathaway (B shares), and short December 2020 $210 calls on Berkshire Hathaway (B shares). The Motley Fool has a disclosure policy.Source