When you want to place a buy or sell order with your brokerage, you have more choices than you likely first thought. (You'll find lots of brokerage guidance in our Broker Center.) Here are the main kinds of orders you should understand:
Market order: This is for immediate execution at the best price available when the order reaches the marketplace. This is the most common type of order and is nearly always filled, since no price is specified. As an example, you might call your broker and bark into the phone, "Buy me 75 shares of Scrunchie Manufacturing (ticker: SCRNCH) at the market!"
Limit order: This is an order to buy or sell only at a specified price (the limit) or better. Investors who have a maximum or minimum price at which they're willing to trade use limit orders. As an example, imagine that Amalgamated Chorus Girls (ticker: KICKK) is trading at $35, and you want to buy, but not at the current price. You might click over to your brokerage's website and place an order to buy 50 shares of KICKK at a limit of $33 per share. This means that if KICKK hits $33 during the day and your order is next in line to be filled, it will be filled at that price. With a limit order, you'll only pay $33 or less per share if your order is filled.
Fill or kill: This order is submitted for immediate execution. If it cannot be filled immediately, it's automatically canceled.
Day order: This order terminates automatically at the end of the business day if it hasn't been filled.
Good till canceled (GTC): This order remains in effect until cancelled by the customer or executed by the broker. It doesn't typically remain in effect forever, though; many brokerages cancel GTC orders after a month or two.
All or none (AON): This is a limit order whereby the broker is directed to attempt to fill the entire amount of the order or none of it. An all-or-none order differs from a fill-or-kill order; with an all-or-none order, immediate execution is not required.
Stop order: This becomes a market order when a specified price is reached or passed. Buy stops are entered above the current market price; sell stops are entered below it. For example, you might place a stop order to have your shares of Stained Glass Windshield (ticker: STAIN) automatically sold if the price falls to less than $40 per share. A stop order guarantees execution but not price.
Stop limit order: This is similar to a stop order, but it becomes a limit order instead of a market order when the price is reached or passed. When you place a "sell 100 XYZ $55 stop limit" order, if XYZ drops to $55 per share or below, the order becomes a limit order to sell 100 shares at no less than $55.
There are tradeoffs with each option. Selling at the market means your shares will probably be sold quickly, but the price may be a little higher or lower than you expected (sometimes a considerable difference). With a limit order, you specify how much you're willing to pay or accept, but you risk not getting any takers at your price.
To learn more about brokerages and find a better one for yourself, check out our Broker Center. And if you've got short-term money to invest, learn how to make the most of it in our Savings Center (which offers Fools special deals on interest rates).