Definition for : Semi-strong efficient market
A semi-strong Efficient market reflects all publicly available information, as found in annual reports, newspaper and magazine articles, prospectuses, announcements of new contracts, of a Merger, of an increase in the Dividend, etc. A semi-strong Efficient market is better than a Weak-form efficient market because current prices have to include historical information (as assumed by the Weak-form efficient market) and publicly available information. See also Efficient market.
(See Chapter 15 The financial markets of the Vernimmen)
To know more about it, look at what we have already written on this subject