Semi-strong market efficiency
From ACT Wiki
One form of the Efficient Market Hypothesis (EMH). The EMH is the general hypothesis that markets operate efficiently. In other words that assets are fairly priced by the market mechanism to incorporate available information.
There are three forms of potential efficiency: the weak form, the semi-strong form and the strong form. The semi-strong form states that prices react to public information so that any form of analysis using publicly available information cannot be successful in consistently generating excess returns.
See also