Characterizing the behavior of a random variable that is, essentially, equally likely to rise as to fall at each step. Since in an efficient market, the price of an asset such as a currency already em [..]

Theory that stock price changes from day to day are accidental or haphazard; changes are independent of each other and have the same probability distribution. For a simple random walk, the best foreca [..]

A time series in which the value of the series in one period is the value of the series in the previous period plus an unpredictable random error.Related Terms: Time series 

Theory that market prices move randomly around a main trend, in other words, that the volatility is arbitrary.

The path taken by an object that moves in steps where each step is determined randomly.

An economic theory that price movements in the commodity futures markets and in the securities markets are completely random in character (i.e., past prices are not a reliable indicator of future pric [..]

A type of stochastic process in which an entity (e.g., a molecule, a animal, a stock price) follows a path consisting of  a series of steps in random directions. For very small steps, a completely ran [..]

Random walk is an economic theory which assumes that market price movements move randomly and new information comes to the market randomly. The theory implies that market prices move randomly as new i [..]

A zero-mean Gaussian stochastic process with stationary independent increments and with standard deviation that grows as the square root of time.

A stochastic path consisting of a sequence of random steps, defined by direction and step size.

A time series process where next period's value is obtained as this period's value, plus an independent (or at least an uncorrelated) error term.

A mathematical model of a series of random steps, used to describe random genetic drift and some other biological processes.

A random walk is a random process yt like: yt=m+yt-1+et where m is a constant (the trend, often zero) and et is white noise. A random walk has infinite variance and a unit root.

Theory that stock price changes from day to day are accidental or haphazard; changes are independent of each other and have the same probability distribution. For a simple random walk, the best foreca [..]