EN
The aim of the article is to examine beta coefficient of WIG20's shares stability. Beta coefficient provides systematic risk measurement, so it's stability is a key factor for effective portfolio management based on beta coefficient. Research reveals beta coefficients high volatility throughout test period of 2001-2012, in particular under financial crisis conditions. Proposed beta coefficient stability ranking reflects combined results of different stability measures: standard deviation, coefficient of variation and mean absolute deviation. Stability ranking is a simple approach to gain some level of statistical objectivity. However, in general beta coefficients of WIG20's shares are highly volatile, what can affect investment portfolio risk and return management.