BOSTON ( TheStreet) -- Seth Klarman, founder of Boston-based hedge fund Baupost Group, is followed closely because his investment philosophy is irreverent and his long-term performance is outstanding. The press-wary guru, who manages more than $20 billion, disclosed first-quarter holdings over the weekend. Klarman is a value investor.Klarman's investment manual, Margin of Safety: Risk-Averse Value Investing Strategies for the Thoughtful Investor, only in publication briefly, now fetches thousands of dollars in the secondary market as his value investing insight is considered second-to-none. Baupost held just 16 stocks as of March 31. It sold out of its position in Regeneron Pharmaceuticals ( REGN), which has appreciated 62% in 2011 and 125% in 12 months, with, presumably, a hefty profit. Baupost decreased its position in four stocks: Enzon Pharmaceuticals ( ENZN), CapitalSource ( CSE), Breitburn Energy ( BBEP) and Ituran Location ( ITRN). It amplified its stakes in PDL BioPharma ( PDLI) and AVEO Pharma ( AVEO). ANV) and Sycamore Networks ( SCMR). His position in Allied Nevada, was substantial, worth $87 million and accounting for 4.9% of the portfolio. His stake in Sycamore, on the other hand, is modest, at $2.4 million, or just 0.1% of the portfolio. Still, Klarman vets all investment ideas thoroughly before purchasing, so it's possible he's still building a stake in Sycamore. His bet on Allied Nevada likely got off to a rocky start as its stock is down 15% in the past month, in part due to a commodities sell-off. Here's a look at these picks.