Warren Buffett, one of the world's most renowned investors, has been making waves with his recent stock activities. In Q3, he was a net seller of stocks for the eighth consecutive quarter. However, his investment managers, Ted Weschler and Todd Combs, have been putting Berkshire Hathaway's massive cash stockpile to work. Let's take a closer look at the stocks he has been buying and how they stack up against each other.

Unraveling Buffett's Recent Stock Moves

Berkshire Hathaway's New Positions

In the last quarter, Berkshire Hathaway initiated new positions in only two stocks. The largest addition was 1.28 million shares of pizza franchiser Domino's Pizza (DPZ 3.36%). At the end of Q3, Berkshire's stake in Domino's was worth $549.4 million. This shows Buffett's confidence in the pizza industry. Domino's has been growing steadily, with a year-to-date gain of less than 5%. It offers a stable dividend with a forward yield of 1.4%, making it an attractive option for income investors.The conglomerate also dipped its toes in the water with swimming pool supplies distributor Pool Corporation (POOL 0.40%). Berkshire bought over 404,000 shares of Pool valued at nearly $152.3 million at the end of Q3. Pool is somewhat more expensive with its shares trading at 29.8 times forward earnings. However, it has its own market share and potential for growth.

Increased Positions in Existing Holdings

Besides the new positions, Berkshire increased its positions in only two existing holdings. Its stake in satellite radio operator Sirius XM Holdings (SIRI -2.64%) increased by 6.99%. Some of this increase was due to the merger of Sirius XM and Liberty SiriusXM Holdings. Berkshire previously owned shares of the two tracking stocks reflecting Liberty Media's interest in Sirius XM. But Buffett or his investment managers also bought more shares in October. Sirius XM has a bargain-basement forward price-to-earnings ratio of 7.3, making it an attractive value play.Finally, Berkshire boosted its position in Heico (HEI -0.28%) by 0.52% in Q3 after first buying shares in Q2. The conglomerate's stake in the aerospace and electronics company was worth roughly $214 million at the end of the quarter. Heico has a sky-high forward earnings multiple of 63.7, which indicates potential for high growth.

Performance Comparison

If we only focus on performance this year, Heico would beat the other recent Buffett additions handily. The stock has skyrocketed over 50%. Domino's comes in second with a year-to-date gain of less than 5%. Pool and Sirius XM are in negative territory with declines of around 10% and 53%, respectively. But when we look at valuations, the picture looks much different. Sirius XM Holdings has a bargain-basement forward price-to-earnings ratio of 7.3. Domino's again grabs the second spot with a forward earnings multiple of 24.3. Pool is somewhat more expensive with its shares trading at 29.8 times forward earnings. Heico is the outlier with a sky-high forward earnings multiple of 63.7.Analysts also have different opinions on how well each stock will perform over the next 12 months. Sirius XM comes out on top with an average price target reflecting an upside potential of 11.6%. Domino's is close behind with analysts thinking the stock could jump 11.4%. Wall Street looks for Pool's shares to rise 6.4% over the next 12 months. Meanwhile, the average price target for Heico is 2.5% below its current share price.All four stocks pay dividends. Sirius XM's dividend is especially juicy with a forward yield of 4.2%. Domino's and Pool are neck-and-neck with forward dividend yields of 1.4% and 1.3%, respectively. Heico comes in last place with a paltry yield of 0.08%.

The Best of the Bunch

Among these stocks, Domino's is a great stock to buy and hold for the long term. Its stable business and growing market share make it a reliable investment. However, if we had to pick the best of the bunch among Buffett's recent buys right now, it would have to be Sirius XM Holdings. Sirius XM is the obvious choice for income and value investors. Its growth prospects look good, with analysts expecting a whopping 150.9% increase in earnings next year.But it's important to note that Sirius XM is not the best stock overall among all Buffett's holdings. There are several stocks in Berkshire's portfolio that may offer better opportunities, such as Amazon.John Mackey, former CEO of Whole Foods Market (an Amazon subsidiary), is a member of The Motley Fool's board of directors. Keith Speights has positions in Amazon, Apple, and Berkshire Hathaway. The Motley Fool has positions in and recommends Amazon, Apple, Berkshire Hathaway, and Domino's Pizza. The Motley Fool recommends Heico. The Motley Fool has a disclosure policy.