Most stock markets work through an auction process, with buyers placing bids for the price they are willing to pay for a stock, and sellers setting an ask price for how much they are willing to sell for. When the two prices meet a trade is conducted and shares exchange hands. In the past all of these trades were made on stock market floors, using an open outcry system where the market makers would yell, or cry out, the prices at which shares could be bought or sold. That has evolved into an electronic auction system, which is good since stock markets today consist of millions of individuals, all of whom have their own ideas of what a stock is worth.