# Random walk

## Random walk :

A random walk is a mathematical concept that describes the movement of an object or a series of events as a sequence of random steps. It is often used to model the behavior of financial markets, where prices tend to move randomly over time, influenced by various factors such as economic conditions, political events, and investor sentiment.
One example of a random walk is the movement of a stock price over time. For instance, consider a company whose stock price starts at \$50 per share. Over the course of a year, the stock price might fluctuate due to a variety of factors such as earnings reports, market trends, and changes in the company’s management or strategy. The stock price might increase or decrease by a few dollars on any given day, but the overall trend is unpredictable. This is because the stock price is influenced by a large number of variables, and it is impossible to predict with certainty how these variables will interact and affect the price.
Another example of a random walk is the movement of a person walking through a crowded city. As the person walks down the street, they encounter a variety of obstacles such as other pedestrians, street signs, and buildings. The person might choose to walk in a straight line, or they might change course to avoid obstacles or take a more interesting route. The person’s movement is influenced by a large number of variables, and it is impossible to predict with certainty how they will move from one step to the next.
Both of these examples illustrate the fundamental concept of a random walk: the movement of an object or series of events is influenced by a large number of variables, and the outcome is unpredictable. This concept has important implications for financial markets and other areas where randomness plays a role.
One of the key properties of a random walk is that it has no “memory.” This means that each step is independent of the previous step, and the future direction of the walk is not influenced by the past. For example, in the stock market, the price of a stock today is not influenced by the price of the stock yesterday. Instead, the price is influenced by a variety of factors such as earnings reports, market trends, and investor sentiment. Similarly, in the case of the person walking through a city, the person’s next step is not influenced by the direction they took on the previous step. Instead, the person’s next step is influenced by the obstacles and opportunities they encounter at that moment.
Another important property of a random walk is that it tends to “diffuse” over time. This means that the distance traveled by the object or series of events tends to increase as time goes on. For example, in the stock market, the price of a stock might fluctuate up and down over time, but the overall trend is for the price to drift further and further away from the starting point. Similarly, in the case of the person walking through a city, the person might zig-zag back and forth, but the overall trend is for the person to travel further and further away from their starting point.
The concept of a random walk has important implications for financial markets and other areas where randomness plays a role. For instance, in the stock market, investors often use random walk models to help them understand the behavior of prices over time and make more informed investment decisions. Similarly, in the case of the person walking through a city, understanding the concept of a random walk can help them plan their route and navigate through the city more effectively.
Overall, the concept of a random walk is a useful tool for understanding the behavior of objects or events that are influenced by a large number of variables and are unpredictable. Whether it’s the movement of a stock price, the movement of a person through a city, or any other situation.