Efficient market

PrepNuggets

An efficient market is one in which asset prices reflect new information quickly and rationally.  

If we look at it from the perspective of statistics, this means that current market prices are unbiased estimates of their values.  The expected return on any asset is just the equilibrium return necessary to compensate investors for the risk regarding its future cash flows.

See also: Strong-form efficient market, Semi-strong-form efficient market, Weak-form efficient market hypothesis