Understanding a Trailing Limit if Touched Order
I don't think user4358's explanation is correct.  A trailing LIT Sell Order adjusts downwards, i.e. if you place the order with an Aux price (in TWS it's trigger price) of 105.00 and a trailing amount of 6.00 then, assuming the ask is 100.00, TWS will add the trailing amount to the ask price and if it's less than the trigger price it will adjust. So in my example, if the market (ask) goes straight up to 105.00, nothing will be adjusted, the trigger is touched and the limit order will be placed (see below). If on the the other hand the market goes down to 99.00 then trlng amt + ask is 105.00, if it goes further down to 98.00 then the trigger price will be adjusted to 104.00 (because it's less than the current trigger), and so on. For the LIT part you have either an absolute limit price you can enter, or you have an offset limit which will be subtracted from the trigger price, in which case it is adjusted as well. So back to my example, the trigger is now 104.00 and the limit offset is say 1.00, so my limit order would be placed at 103.00 if the ask ever touches 104.00, and that in turn is only visible if the bid touches 103.00 (because it's limit-if-touched). For a buy just use the same explanation with some swapped roles, the trigger price adjust upwards when the trailing amount plus bid is larger than the current trigger, and the limit offset will be added to the trigger price. Edit Also quite succinct and worth having a look at: http://www.interactivebrokers.com/en/trading/orders/trailingLimitTouched.php Guesswork, highly subjective As for why this might be good, well, you have to believe in momentum strategies, i.e. a market that goes down, will continue to go down, if you believe that and you believe in mean reversion as well, then a trailing limit order can assist you in not buying/selling impulsively, but closer to the mean.  I've never used it that way though. What I have done, even just now to get the explanation right, is to place trailing buy and sell orders simultaneously.  You will find that you can just go in with coarse estimates and because the adjustments will go towards each other, you will end up with a narrowing band of trigger prices (as opposed to trailing stop orders which will give you a widening band of trigger prices).  If you believe in overshooting and equilibria then this can be one easy way to profit from it.  I've just sold EURUSD for 1.26420 and bought it back at 1.26380 with a trailing amount of 5pips and a limit offset of 2pips within the time of writing this. This is rather simple if you understand a trailing limit order but to be sure I am going to explain a limit, trailing limit, and trailing LIT order. I am going to use an example assuming that you already own a stock and want to sell it. Limit Order I place an order to sell 100 PG @ 65.00. This order will only be executed if the bid price of PG is at $65.0000 or greater. Trailing Limit Order I place an order to sell 100 CAT @ 85.25 with a trailing 5%. This order will be executed when CAT drops 5% below the highest point it reaches after you place this order. So if you place this order at 85.25 and the stock drops 5% to $80.9875, your order will be executed. However, if the stock jumps to $98, the order will not be executed until the stock falls to $93.10. The sell point will go up with the stock and will always remain at the specified % or $ amount behind the high point. Trailing Limit If Touched Order I place an order to sell 100 INTC @ 24.75 with a trailing 5% if the stock touches $25.00. Essentially, this is the same as the trailing limit except that it doesn't take effect until the stock first gets $25.00.  I think the page they provide to explain this is confusing because I think they are explaining it from the shorting a stock perspective instead of the selling a stock you want to profit from. I could also be wrong in how I understand it. My advice would be to either call their customer support and ask for a better explanation or what I do in my finances, avoid things I don't understand.
"I think that pattern is impossible, since the attempt to apply the second half would seem to prevent executing the first. Could you rewrite that as ""After the stock rises to $X, start watching for a drop of $Y from peak price; if/when that happens, sell."" Or does that not do what you want? (I'm not going to comment on whether the proposed programmed trading makes sense. Trying to manage things at this level of detail has always struck me as glorified guesswork.)" "An attempt at a simple answer for the normal investor: A normal investor buys stock then later sells that stock. (This is known as ""going long"", as opposed to ""going short"").  For the normal investor, a stop order (of either kind) is only used when selling. A stop-loss sell order (or stop sell) is used to sell your stock when it has fallen too much in price, and you don't want to suffer more losses.  If the stock is at $50, you could enter a stop sell at $40, which means if the stock ever falls to $40 or lower, your stock will be sold at whatever price is available (e.g. $35). A stop-loss limit sell order (or stop limit sell) is the same, except you are also saying ""but don't sell for less than my limit price"".  So you can enter a stop limit sell at $40 with a limit of $39, meaning that if the stock falls to $40, you will then have a limit order in effect to sell the stock at $39 or higher.  Thus your stock will never be sold at $35 or any value below $39, but of course, if the stock falls fast from $40 to $35, your limit sell at $39 will not be done and you will be left still owning the stock (worth at that moment $35, say)." It definitely depends on the exchange you are trading on. I'm not familiar with Scottrade, but a standard practice is to fulfill limit orders in the order they are placed.   Most of the time, you wouldn't see stocks trade significantly under your bid price, but since penny stocks are very volatile, it's more likely their price could drop quickly past your bid and then return above it while only fulfilling a portion of the orders placed. Example 1. Penny stock priced at $0.12 2. Others place limit orders to buy at $0.10 3. You place limit order to buy at $0.10 4. Stock price drops to $0.07 and some orders are filled (anything $0.07 or higher) based on a first-come first-served basis 5. Due to the increase in purchases of the penny stock, the price rises above $0.10 before your order is filled ***EDIT*** - Adding additional clarification from comment section. A second example If the price drops from $0.12 to $0.07, then orders for all prices from $0.07 and above will start to be filled from the oldest order first. That might mean that the oldest order was a limit buy order for 100 shares at $0.09, and since that is above the current ask price, it will be filled first. The next order might be for 800 shares at $0.07. It's possible for a subset of these to be filled (let's say 400) before the share's price increases from the increased demand. Then, if the price goes above $0.10, your bid will not be filled during that time. On most exchanges, if you place a limit order to sell at 94.64, you will be executed before the market can trade at a higher price. However most stocks in the US trade across several exchanges and your broker won't place your limit order on all exchanges (otherwise you could be executed several times). The likeliest reason for wht happened to you is that your order was not on the market where those transactions were executed. Reviewing the ticks, there were only 8 transactions above your limit, all at 1:28:24, for a total 1,864 shares and all on the NYSE ARCA exchange. If your order was on a different exchange (NYSE for example) you would not have been executed. If your broker uses a smart routing system they would not have had time to route your order to ARCA in time for execution because the market traded lower straight after. Volume at each price on that day: Traders sometimes look at the depth of the book (number of outstanding limit orders) to try and gauge the sentiment of the market or otherwise use this information to formulate their strategy.  If there was a large outstanding buy order at $49.50, there's a decent chance this could increase the price by influencing other traders. However, a limit order at $2 is like an amazon.com price of $200,000 for a book.  It's so far away from realistic that it is ignored.  People would think it is an error. Submitting this type of order is perfectly legal.  If the stock is extremely thinly traded, it might even be encouraged because if someone wanted to sell a bunch and did a really bad job of it, the price could conceivably fall that far and the limit order would be adding liquidity.  I guess.  Your example is pretty extreme. It is not uncommon for there to be limit orders on the book that are not very close to the trading price.  They just sit around.  The majority of trades are done by algorithmic traders and institutional traders and they don't tend to do this, but a retail investor may choose to submit an order like that, just hoping against hope. Also, buy orders are not likely to push prices down, no matter what their price is.  A sell order, yes (even if it isn't executed). From the non-authoritative Investopedia page: A stop-limit order will be executed at a specified price, or better, after a given stop price has been reached. Once the stop price is reached, the stop-limit order becomes a limit order to buy or sell at the limit price or better. So once the stop price has been breached, your limit order is placed and will be on the order books as a $9 ask. For a vanilla stop order, a market order will be placed and will be filled using the highest active bid(s). There are a few scenarios I see possible:  1. Risk parameters in the algo were set very conservatively. Putting quotes out and canceling them is very common.   2. It was looking to exploit situations where someone rips through the book with a market order.  3. It was reacting too slowly to signals, and chasing opportunities that had already passed.   Other comments: What do you believe front running is? Your version differs from the textbook definition.   Quote taxes are more effective than minimum order durations. I wrote about how that works in a previous post in this thread. A limit order is simply an order to buy at a maximum price or sell at a minimum price. For example, if the price is $100 and you want to sell if the price rises to $110, then you can simply put a limit order to sell at $110. The order will be placed in the market and when the price reaches $110 your order will be executed. If the price gaps at the open to $111, then you would end up selling for $111. In other words you will get a minimum of $110 per share. A stop limit order is where you put a stop loss order, which when it gets triggered, will place a limit order in the market for you. For example, you want to limit your losses by placing a stop loss order if the price drops to $90. If you chose a market order with your stop loss as soon as the price hits $90 your stop loss would be triggered and the shares would sell at the next available price, usually at $90, but could be less if the market gaps down past $90. If on the other hand you placed a limit order at $89.50 with your stop loss, when the stop loss order gets triggered at $90 your limit order will be placed into the market to sell at $89.50. So you would get a minimum of $89.50 per share, however, if the market gaps down below $89.50 your order will be placed onto the market but it won't sell, unless the price goes back to or above $89.50. Hope this helps. Firstly what are you trading that you could lose more than you put in? If you are simply trading stocks you will not lose more than you put in, unless you are trading on margin. A limit order is basically that, a limit on the maximum price you want your buy order bought at or the minimum price you want your sell order sold at. If you can't be glued to the screen all day when you place a limit order, and the market moves the opposite way, you may miss out on your order being executed. Even if you can be in front of the screen all day, you then have to decide if you want to chase the market of miss out on your purchase or sale. For example, if a stock is trading at $10.10 and you put a limit buy order to buy 1000 shares at or below $10.00 and the price keeps moving up to $10.20, then $10.30 and then $10.50, until it closes the day at $11.00. You then have the choice during the day to miss out on buying the shares or to increase your limit order in order to buy at a higher price. Sometime if the stock is not very liquid, i.e. it does not trade very often and has low volume, the price may hit $10.00 and you may only have part of your order executed, say 500 out of your 1000 shares were bought. This may mean that you may have to increase the price of your remaining order or be happy with only buying 500 shares instead of 1000. The same can happen when you are selling (but in reverse obviously). With market order, however, you are placing a buy order to buy at the next bid price in the depth or a sell order to sell at the next offer price in the depth. See the market depth table below:  Note that this price depth table is taken before market open so it seems that the stock is somewhat illiquid with a large gap between the first and second prices in the buyers (bid) prices. When the market opened this gap is closed, as WBC is a major Australian bank and is quite liquid. (the table is for demonstration purposes only). If we pretend that the market was currently open and saw the current market depth for WBC as above, you could decide to place a limit sell order to sell 1000 shares at say $29.91. You would sell 100 shares straight away but your remaining 900 sell order will remain at the top of the Sellers list. If other Buyers come in at $29.91 you may get your whole sale completed, however, if no other Buyers place orders above $29.80 and other Sellers come into the market with sell orders below $29.91, your remaining order may never be executed. If instead you placed a market sell order you would immediately sell 100 shares at $29.91 and the remaining 900 shares at $29.80. (so you would be $99 or just over 0.3% worse off than if you were able to sell the full 1000 shares at $29.91). The question is how low would you have had to lower your limit order price if the price for WBC kept on falling and you had to sell that day? There are risks with whichever type of order you use. You need to determine what the purpose of your order is. Is it to get in or out of the market as soon as possible with the possibility of giving a little bit back to the market? Or is it to get the price you want no matter how long it takes you? That is you are willing to miss out on buying the shares (can miss out on a good buy if the price keeps rising for weeks or months or even years) or you are willing to miss out on selling them right now and can wait for the price to come back up to the price you were willing to sell at (where you may miss out on selling the shares at a good price and they keep on falling and you give back all your profits and more). Just before the onset of the GFC I sold some shares (which I had bought a few years earlier at $3.40) through a market order for $5.96. It had traded just above $6 a few days earlier, but if instead of a market order I had placed a limit order to sell at $6.00 or more I would have missed out on the sale. The price never went back up  to $6 or above, and the following week it started dropping very quickly. It is now trading at about $1.30 and has never gone back above $2.00 (5.5 years later). So to me placing a limit order in this case was very risky. If you are buying your order will be placed in Bid list. If you are selling your order will be placed in the Ask list. The highest Bid price will be placed at the top of the Bid list and the lowest Ask price will be placed at the top of the Ask list. When a Bid and Ask price are matched a transaction will take place and it will the last traded price. If you are looking to buy at a lower price, say $155.01, your Bid price will be placed 3rd in the Bid list, and unless the Ask prices fall to that level, your order will remain in the list until it trades, it expires or you cancel it. If prices don't fall to you Bid price you will not get a trade. If you wanted your trade to go through you could either place a limit buy order closer to the lowest Ask price (however this is still not a certainty), or to be certain place a market buy order which will trade at the lowest Ask price. "This is called a Contingent Order and is set up so if one order is filled (in this case) the other order is cancelled.  It's a common desire that one would wish to have a stop-loss in place but also a targeted sell price for their in-the-money sell point.  Your broker will tell you all you need to know about how to enter this, if you explain you'd like to place a contingent order. (As Victor noted below, your specific order would be a ""One Cancels Other"" or ""OCO"") Great first question, welcome to Money,SE." Stop order is triggered when the market reaches the price you set. Until then - its not on the books. Your understanding is wrong in that you don't go to read the definition of the term. If you want to buy once the price goes up to $101 or above you can place a conditional order to be triggered at $101 or above and for a limit order to entered to buy at $102. This will mean that as soon as the price reaches $101 or above, your limit order will enter the market and you will buy at any price from $102 or below. So if the price just trickles over $101 you will end up buying at around $101 or just over $101. However, if the price gaps above $101, say it gaps up to $101.50, then you will end up buying at around $101.50. If the price gaps up above $102, say $102.50, then your limit order at $102 will hit the market but it will not trade until the price drops back to $102 or below. I would be using stop limit orders for stocks that are not too volatile. If you look at the chart and there are not many gaps especially after peaks, then you have more chance of being filled at your specified stop loss level using a stop limit order. If the stock is very volatile and has a large or many gaps down after most peak, then I would consider using a stop market order to make sure you do get out even if it is somewhat past your desired stop level. One think to consider is to avoid trading very volatile stocks that gap often. This is what I do, and using stop limit orders my stop level is achieved more than 95% of the time. I assume you're talking about a sell order, not a buy order. When you place a limit sell order, your order is guaranteed to be placed at that price or higher.  If the market is currently trading much higher than the price of your sell order, then your mistakenly low limit order will be essentially a market order, and will be filled at  the current bid price. So the only way this is a problem is if you want to place a limit sell that is much higher than the current market, but mistakenly place a limit lower than the current market.