How to Calculate Market Price Change of Common Stock

How to Calculate Market Price Change of Common Stock
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Shares of a company’s common stock represent an ownership interest in the company. The shares can trade on a stock exchange, or over the counter through a network of dealers. A company’s common stock price is the price investors are willing to pay for a single share of stock. The market price fluctuates as investors buy and sell shares. If your company owns stock, your team will likely want to occasionally check in on how your stock is performing on the market. You can calculate the change in the market price of a common stock to measure an investment’s performance.


  • Calculating the market price change of common stock can be accomplished relatively easily. In order to dos, you can subtract the previous stock price from the current price, which will give you a positive or negative number reflective of price changes. This number can then be divided into the previous price and multiplied by 100 to give a percentage reflective of the change.

Researching Stock Value

To get started, go online and find your favorite financial website that provides stock information. Type your company’s name or ticker symbol in the text box required to search for the company’s stock information. A ticker symbol consists of letters that are an abbreviation of a company’s name or something related to a company’s business. Then click the button next to the text box to bring up the company’s current stock price. For example, assume a company’s current stock price is $14. You'll see that information in the box.

Determining Historic Value

Once you've seen a stock's current value, you'll need historic value in order to compare. Click on the historical prices section of the company’s stock quote information. Find the company’s stock price on a previous date, such as the date on which you purchased the stock. In this example, assume the company’s stock price was $10 one year ago.

Calculating Change in Price

Subtract the previous stock price from the current stock price to calculate the change in price. A positive result means the stock’s price increased. A negative number means the stock has decreased in price. In this example, subtract $10 from $14 to get $4. This means the stock’s price increased by $4. Divide the change in stock price by the previous price. Then multiply the result by 100 to calculate the percentage change in stock price. Continuing with the example from the previous steps, divide $4 by $10 to get 0.4. Multiply 0.4 by 100 to find a 40 percent increase in the stock’s price.

Following Up on Your Investments

Once you've arrived at a figure, it's important to be aware that it will change on an ongoing basis. You'll need to perform this calculation regularly to remain aware of how your stock is performing over the course of months and years.