NEW YORK ( TheStreet) -- Glenn Tongue, co-manager of the Tilson Focus Fund ( TILFX), says Berkshire Hathaway's ( BRK.B) stock remains cheap despite recent gains. Shares of Warren Buffett's investment company could keep climbing, he says.The $16 million fund, which garners three stars from Morningstar ( MORN), has doubled during the past year, better than 98% of rival funds. The fund has climbed 5.7% annually, on average, during the past five years, outperforming 88% of competitors. Welcome to TheStreet's Fund Manager Five Spot, where America's top mutual fund managers give their best stock picks in five fast and furious questions. Are you finding value in the market right now? Tongue: Absolutely. A year ago it was real easy. A year ago the challenge was to stay invested. You have to be much more selective now but there are great opportunities if you are willing to do the work to dig into these companies. Is Berkshire Hathaway still a buy? It's had a nice little spike since the split. Tongue: It's had a nice run. It's still our largest position and we think it is cheap. It's safe, it's fast growing and it's cheap. The operating businesses are worth about $40 per share. And the cash and marketable securities like Coca-Cola ( KO) and American Express ( AXP) on the balance sheet, we think are worth about $60 a share. So that's maybe $100 a share that the company is worth and it's trading at around $80 a share. What's your view on General Growth Properties (GGP)? What do you think the end game is? Tongue: Well, General Growth was a dollar a share a year ago and it's now $15 a share. But for an acquirer like Simon Properties ( SPG) it's worth well over $20 a share. So I expect they are going to come back with an attractive bid and there are also other suitors in the wings. Boston Scientific (BSX) has been having some big problems recently. You are getting into the stock. Why? Tongue: It's all a question of price. Any company out there is worth a certain value, and Boston Scientific got down to our threshold. We thought at $7 to $8 a share it was interesting opportunity. And when it dropped by over a dollar a few days ago it became a high priority opportunity for us. Another stock you like is Iridium Communications (IRDM). The original Iridium was in bankruptcy a while ago. It has since come back. Why do you like this stock? Tongue: You're right. It was in bankruptcy, but it was a different company back then. It was a consumer-based company. This stock is about the cheapest company we have in our portfolio and one of the cheapest we have seen in many years. It's trading at about 3 times operating cash flow. It is growing at 20% a year. It generates about $150 million in cash every year. We think this company is extraordinarily cheap, very well run and has a huge runway for many years. -- Reported by Gregg Greenberg in New York.