After reading «The Intelligent Investor», he studied under the author and university professor Benjamin Graham at Columbia University in New York until 1951. Graham’s teachings strongly influenced Buffett and – according to himself – changed his investment philosophy as well as his life significantly.
After his study years, Buffet worked as seller of shares at «Buffett-Falk & Company» until 1954 and then as equity analyst in the Graham-Newman Corporation of his role model and mentor Benjamin Graham in New York. In 1956, he founded his own asset management company in Omaha, with a starting capital of USD 100,000 – which he liquidated in 1969.
Between 1956 and 1969, his clients could increase their assets 30-fold. In 1965, Buffett purchased the textile company Berkshire Hathaway, which he then expanded to a holding for various stakes. He offered the clients of his previous asset management the possibility of investing their funds in Berkshire shares at USD 43 per share. Until today, Buffet holds more than a quarter of all shares himself.
Buffett is a classical value investor and, as such, largely stayed faithful to Graham’s principles. He analyses the key data of a company in order to define the net asset value of a share. If the stock price is below the net asset value, a purchasing potential exists. Thereby, Buffet only invests in companies with a business model he understands – for example insurance companies – and with a management that he deems capable.