http://coinmamailtcrg7fw6uorut3d35bk35rtmntkrtb4fgeov6pefvfutqd.onion/blog/is-using-a-bitcoin-exchange-safe
In many ways, a Bitcoin exchange functions exactly the way the stock market functions: users will place a “market order” which asks the exchange to buy BTC on their behalf at the best possible price, or they’ll place a “limit order” which allows the exchange to buy coins on their behalf at the best possible price up to a specified maximum, or to sell them for the most money down to a specified minimum.