The prices of shares on a stock market can be set in a number of ways but most the most common way is through an auction process where buyers and sellers place bids and offers to buy or sell a. For investors the stock market works like an auction where buyers place bids and sellers offer asking prices for shares of stock when the bid equals the ask a trade occurs. However no one actually sets a stocks prices the value of a stock is expressed through how investors handle them so the price of a stock is ultimately determined by supply and demand the price listed online is the fair price determined by which price the most trades take place. The stock market serves two very important purposes the first is to provide capital net working capital net working capital nwc is the difference between a companys current assets net of cash and current liabilities net of debt on its balance sheet