Open end funds for private investors offer in general daily redemption of outstanding shares. A high liquidity of shares is in sharp contrast to the illiquidity of real estate. Therefore, the typical construction for real estate funds which are designed for a broader public is closed ended. Attempts to establish open end funds have regularly let to crises comparable to bank runs, e.g. the RODAMCO case in the Netherlands, or the actual crisis of German open end funds. Liquidity transformation as a typical function of banks also bears inevitably to the danger of bank runs. Therefore we offer a framework based on the recent works in bank theory of Diamond/Dybvig (1983), Allen/Gale (1998), and Diamond/Rajan (2001) which examine whether open end funds can represent a stable investment design for real estate. Furthermore we show that the open end construction delivers a monitoring function with respect to the fund managers.