Order types: market, limit, stop, stop limit

In short

You have probably stood at a diner counter and just said "give me the usual" without asking the price. That is a market order. You handed over control of the exact number to someone else. Sometimes that works out fine. Sometimes the bill surprises you. Knowing your four basic order types is like reading the menu before you sit down. It puts you in charge of the trade before the trade happens.

The whole of it

What it is

A friend of mine once bought a stock in a hurry. He clicked fast, did not look at the type of order selected, and paid more than he expected. He felt foolish, but the truth is almost everyone does this at least once. An order type is simply an instruction. You send it to your brokerage, and the brokerage sends it to the market. The instruction tells two things: at what price you are willing to trade, and under what conditions the trade should even happen at all. There are four common types. A market order says buy or sell right now at whatever price is available. A limit order says buy or sell only at a specific price or better. A stop order says wait until the price reaches a trigger, then send a market order. A stop limit order says wait until the price reaches a trigger, then send a limit order instead of a market order.

How it works

I once watched a busy auction and noticed that speed and price are always trading places with each other. You can have one, but giving up the other is the cost. That tension is exactly what these four order types are managing for you.

A market order is the fastest. You place it, and it fills almost immediately during normal trading hours. The catch is you do not know the exact price until after the fill. The price you see on screen is called the quote. The price you actually get is called the execution price. When a stock trades millions of shares a day, those two numbers are usually very close. When a stock trades only a few thousand shares a day, the gap can be wide. That gap has a name. It is called the bid ask spread, which simply means the difference between what a buyer will pay and what a seller will accept.

A limit order lets you name your price. You want to buy shares of a company, and you decide you will not pay more than 40 dollars per share. You set a limit buy at 40. If the price comes down to 40, your order fills. If it never drops that low, your order sits there waiting, and it may never fill at all. That is the honest cost of control. You get the price or you get nothing. A limit sell works the same way in reverse. You will not sell for less than your chosen price.

A stop order is sometimes called a stop loss, which tells you exactly what most people use it for. You already own shares. You are worried the price might fall hard. You set a stop at, say, 35 dollars. If the price drops to 35, the stop triggers and a market order goes out automatically. You do not have to watch the screen. The problem is that in a fast moving market, the market order that fires might fill at 33 or 32, not 35. The trigger and the fill are two different events.

A stop limit order tries to solve that problem by adding a floor. The stop triggers at one price, but instead of a market order firing, a limit order fires with its own minimum. You set a stop at 35 and a limit at 34. If the price drops to 35, a limit order goes out with a floor of 34. You will not sell below 34. The risk is that if the price falls through 34 too fast, the order may not fill at all. You kept your price but lost your exit. Neither stop orders nor stop limit orders are guarantees.

The numbers, and where to find yours

You have probably noticed I have not quoted a single dollar threshold or contract size, and that is on purpose. Order types themselves carry no official cost set by law. But the costs that touch them do matter, and they change. Your brokerage may charge a commission per trade. Brokerages may also receive payment for order flow, which is a practice where a market maker pays your broker for sending orders its way. The market maker profits from the bid ask spread; the payment for order flow is a separate rebate the broker receives. The Securities and Exchange Commission, at sec.gov, explains payment for order flow and requires brokerages to disclose it. FINRA, at finra.org, publishes guidance on best execution, which is the rule that says your broker must try to get you a fair fill. Read your brokerage's own fee schedule before placing your first order. That document is the only number that applies to your account.

A worked example

Maria has saved carefully and now holds 100 shares of a company she believes in. She paid 50 dollars a share. The stock now trades at 58 dollars. She is happy but nervous. She does not want to lose the gain if the stock drops sharply while she is at work.

Maria places a stop limit order. She sets the stop trigger at 54 dollars and the limit floor at 52 dollars. As long as the stock stays above 54, nothing happens. One afternoon the stock falls to 54. Her stop triggers. A limit order fires with a floor of 52. The stock keeps sliding and fills her order at 53 dollars per share. She sells all 100 shares at 53. Her total proceeds are 5,300 dollars before any commissions or taxes. She originally paid 5,000 dollars for those shares. She locked in a gain of 300 dollars, minus whatever her brokerage charges per trade.

Now consider what would have happened with a plain stop. The stop triggers at 54. A market order fires. But news breaks at the same moment and the stock gaps down fast. The fill comes back at 49 dollars, below what she paid. A market order gave her speed but cost her the price. Neither outcome is wrong. They are just different instructions with different results.

Where it goes wrong

I once read about a man who set a stop loss on a thinly traded stock and forgot about it for weeks. He assumed it was protecting him. It was sitting there, never having triggered, while the stock drifted lower in a slow, quiet way that never hit his exact stop price. Stops do not protect against slow decay. They protect against sudden drops past a trigger point.

Limit orders go wrong when people set them and walk away assuming they will fill. The price may never reach your limit. Opportunity passes. Market orders go wrong in thin markets, meaning stocks that do not trade much, where the bid ask spread is large and your fill price shocks you. Stop limit orders go wrong in fast markets when the price blows straight through both the stop and the limit without pausing, leaving your order unfilled and your position still open.

One quiet truth here. No order type predicts the future. Each one just carries out a specific instruction under specific conditions. Know the condition before you choose the type.

Questions to answer before you leave this page

Before you place your next order, sit with these honest questions for a moment: Do you need the trade to happen right now no matter what, or is the price more important to you than the speed, and if price matters most, what is the exact number you will not go past? If you own shares and want protection on the downside, have you decided both where your stop triggers and where your limit floor sits, and do you understand that a gap in price could skip right past both? Have you read your brokerage's own fee schedule so you know what each order type costs you in commissions, and have you looked up their policy on payment for order flow on their site or on sec.gov? And finally, is the stock you are trading liquid enough, meaning does it trade enough shares each day, that a market order will fill close to the price you see on screen before you click?