Testing weak form informational efficiency on the Romanian capital market

The informational efficiency of the Romanian capital market was previously studied, by different approaches. The first condition that needs verification is that of weak form informational efficiency. The present paper aims to make contributions in this direction, namely to test weak form efficiency, on a sample composed of recent data, collected from the most liquid companies listed on our country’s capital market. For this approach, we use the unit root tests. The results are useful to potential investors, interested to find out whether they can or cannot obtain excessive earnings, by studying stock prices history.