Bull Market is a term to describe unusual rise in the prices of investments and appreciation in their values. When such rises continue for reasonably long period of time, the market is said to enter the Bull phase. It may result on account of better economic conditions; general boom in the economy; simply on account of general euphoria resulting from the investor psychology or on account of combination of one or more of these and many other factors. In fact, none is sure of the reason and perhaps none can predict accurately the emergence on a Bull Market.
The Bull Market may emerge in a particular stock or a particular commodity or in the stock market in general may enter a bull orbit and prices may move northward. Bull Market is opposite of a Bear Market. In the USA, the 1990s saw emergence of a prolonged Bull Market when equity prices surged ahead and grew at a fast pace.
Bull Market is generally associated with the Stock Markets but it may emerge in any other Financial Market or Commodity Market. You may find an analysis of Bull Market in Gold and Silver here: Bull Market and Gold & Silver.
Perhaps no one can tell anything with certainty about the emergence of Bull Markets. Still, analysts always try to predict the trend and one example is this Power Point Presentation of Standard & Poor’s Investment Outlook.