Now that a week has passed since Berkshire Hathaway (NYSE:BRK-A)(NYSE:BRK-B) reported earnings, in today's Stock of the Day, Motley Fool analyst Brendan Mathews takes a look back at another solid quarter from Berkshire and shares his thoughts about the stock today.

Though Class A shares are famously the most expensive stock on the market from a share-price perspective, Brendan discusses its valuation and why he considers Berkshire to be undervalued. He also lets investors in on the steps he uses to value Berkshire Hathaway.

Ultimately, he sees this as a great collection of businesses that is continuing to grow, with a price-to-tangible book value well below that of the S&P and a share price well below the valuation he gives the stock. In his book, that makes Berkshire a great buy for investors today.

Brendan Mathews owns shares of Berkshire Hathaway. Mark Reeth has no position in any stocks mentioned. The Motley Fool recommends and owns shares of Berkshire Hathaway. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.