This final thesis deals with the stock analysis and stock valuation as the basis of successful investing and managing the portfolio of securities. Since the stocks today would not have such great significance without the existence of financial markets, the final thesis points out the importance of these markets and the stock exchange, where the purchase or sale of stocks is carried out and where the stocks get their market value. The emphasis is placed on the division of the capital markets, securities and stocks. The capital markets, stock markets and securities in Croatia are presented. There are detailed models and theories of stock analysis, as well as equity valuations using different variables that determine the value of the stocks. The thesis also highlights the philosophy and methods of investment in stocks by two well-known and successful international investors - Benjamin Graham and Warren Buffett, who are the main representatives of the so-called "informal" or "non-institutional" way of investing in stock markets.