Buy the open and set a 1% limit sell order
Nothing is wrong and it should be profitable - but it sounds too good to be true. The devil is in the details and you have not described how you found those stocks. For example, you may have scanned the 500 stocks in the S&P 500, and you may have found a few that exhibit that pattern over a given time window. But it doesn't mean that they will continue to do so. In other words they may just be random outliers. This is generically called overfitting. A more robust test would be to use a period, say 2000-2005 to find those stocks and check over a future period, say 2006-2014 if the strategy you describe is profitable. My guess is that it won't. One should also point out that you make a major assumption in that the high of the day doesn't occur on a gap up in morning trading. It's unlikely that you'd fill at a reasonable price, thereby throwing your strategy into disarray.
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. You need to use one of each, so a single order wouldn't cover this:  The stop-loss order could be placed to handle triggering a sell market order if the stock trades at $95 or lower.  If you want, you could use a stop-limit order if you have an exit price in mind should the stock price drop to $95 though that requires setting a price for the stop to execute and then another price for the sell order to execute. The limit sell order could be placed to handle triggering a sell if the stock rises above $105. On the bright side, once either is done the other could be canceled as it isn't applicable anymore. The strategy could conceivably work if you had sufficient quantity of shares to fill all of the outstanding buy orders and fill your lower buy orders.  But in this case you are forcing the market down by selling and reinforcing the notion that there is a sell off by filling ever lower buy orders.  There is the potential to trigger some stop loss orders if you can pressure it low enough.  There is a lot of risk here that someone sees what you are doing and decides to jump in and buy forcing the price back up.  Could this work sure.  But it is very risky and if you fail to create the panic selling then you risk losing big.  I also suspect that this would violate SEC Rules and several laws.  And if the price drops too far then trading on the stock would be halted and is likely to return at the appropriate price. Bottom line I can not see a scenario where you do not trigger the stop, net a profit and end up with as many or more stock that you had in the first place. "There are two distinct questions that may be of interest to you. Both questions are relevant for funds that need to buy or sell large orders that you are talking about. The answer depends on your order type and the current market state such as the level 2 order book. Suppose there are no iceberg or hidden orders and the order book (image courtesy of this question) currently is:  An unlimited (""at market"") buy order for 12,000 shares gets filled immediately: it gets 1,100 shares at 180.03 (1,100@180.03), 9,700 at 180.04 and 1,200 at 180.05. After this order, the lowest ask price becomes 180.05 and the highest bid is obviously still 180.02 (because the previous order was a 'market order'). A limited buy order for 12,000 shares with a price limit of 180.04 gets the first two fills just like the market order: 1,100 shares at 180.03 and 9,700 at 180.04. However, the remainder of the order will establish a new bid price level for 1,200 shares at 180.04. It is possible to enter an unlimited buy order that exhausts the book. However, such a trade would often be considered a mis-trade and either (i) be cancelled by the broker, (ii) be cancelled or undone by the exchange, or (iii) hit the maximum price move a stock is allowed per day (""limit up""). Funds and banks often have to buy or sell large quantities, just like you have described. However they usually do not punch through order book levels as I described before. Instead they would spread out the order over time and buy a smaller quantity several times throughout the day. Simple algorithms attempt to get a price close to the time-weighted average price (TWAP) or volume-weighted average price (VWAP) and would buy a smaller amount every N minutes. Despite splitting the order into smaller pieces the price usually moves against the trader for many reasons. There are many models to estimate the market impact of an order before executing it and many brokers have their own model, for example Deutsche Bank. There is considerable research on ""market impact"" if you are interested. I understand the general principal that when significant buy orders   comes in relative to the sell orders price goes up and when a   significant sell order comes in relative to buy orders it goes down. I consider this statement wrong or at least misleading. First, stocks can jump in price without or with very little volume. Consider a company that releases a negative earnings surprise over night. On the next day the stock may open 20% lower without any orders having matched for any price in between. The price moved because the perception of the stocks value changed, not because of buy or sell pressure. Second, buy and sell pressure have an effect on the price because of the underlying reason, and not necessarily/only because of the mechanics of the market. Assume you were prepared to sell HyperNanoTech stock, but suddenly there's a lot of buzz and your colleagues are talking about buying it. Would you still sell it for the same price? I wouldn't. I would try to find out how much they are prepared to buy it for. In other words, buy pressure can be the consequence of successful marketing of the stock and the marketing buzz is what changes the price." "Limited Price is probably equivalent to the current par value of a ""limit order"". Markets move fast, and if the commodity is seeing some volatility in the buy and sell prices, if you place an ordinary buy order you may not get the price you were quoted. A ""limit order"" tells your broker or whomever or whatever is making the order on your behalf that you will pay no more than X yuan. While the market is below that price, the trader will attempt to get you the quantity you want, but if they can't get you your full order for an average price less than the limit, the whole thing is rolled back. You can set a limit at any price, but a limit order of 1 yuan for a pound of sterling silver will likely never be executed as long as the market itself is functioning. So, you are being provided with a ""par value"" that they can guarantee will be executed in the current market. Entrustment prices are probably prices offered to the managers of trust funds. A trust is simply a set of securities and/or cash which is placed under the nominal control of a third party, who then must in good faith attempt to fulfill the goals of the actual owner of the securities with regards to growth or retention of value. Trustees almost never speculate with the money they control, but when they do move money it's often a sizeble chunk (hundreds of thousands or millions of dollars instead of a few thousand dollars here and there). So, in return for the long-term holdings, large buys and sells, and thus the reduced cost of maintaining a business relationship with the broker, the broker may offer better prices to trust fund managers." "A market sell order will be filled at the highest current ""bid"" price. For a reasonably liquid stock, there will be several buy orders in line, and the highest bid must be filled first, so there should a very short time between when you place the order and when it is filled.   What could happen is what's called front running. That's when the broker places their own order in front of yours to fulfill the current bid, selling their own stock at the slightly higher price, causing your sale to be filled at a lower price.  This is not only unethical but illegal as well. It is not something you should be concerned about with a large broker.   You should only place a market order when you don't care about minute differences between the current ask and your execution price, but want to guarantee order execution. If you absolutely have to sell at a minimum price, then a limit order is more appropriate, but you run the risk that your limit will not be reached and your order will not be filled. So the risk is a tradeoff between a guaranteed price and a guaranteed execution." TD will only sell the stock for you if there's a buyer. There was a buyer, for at least one transaction of at least one stock at 96.66. But who said there were more? Obviously, the stocks later fell, i.e.: there were not that many buyers as there were sellers. What I'm saying is that once the stock passed/reached the limit, the order becomes an active order. But it doesn't become the only active order. It is added to the list, and to the bottom of that list. Obviously, in this case, there were not enough buyers to go through the whole list and get to your order, and since it was a limit order - it would only execute with the limit price you put. Once the price went down you got out of luck.  That said, there could of course be a possibility of a system failure. But given the story of the market behavior - it just looks like you miscalculated and lost on a bet. 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. In order to see whether you can buy or sell some given quantity of a stock at the current bid price, you need a counterparty (a buyer) who is willing to buy the number of stocks you are wishing to offload. To see whether such a counterparty exists, you can look at the stock's order book, or level two feed. The order book shows all the people who have placed buy or sell orders, the price they are willing to pay, and the quantity they demand at that price. Here is the order book from earlier this morning for the British pharmaceutical company, GlaxoSmithKline PLC.  Let's start by looking at the left-hand blue part of the book, beneath the yellow strip. This is called the Buy side. The book is sorted with the highest price at the top, because this is the best price that a seller can presently obtain. If several buyers bid at the same price, then the oldest entry on the book takes precedence. You can see we have five buyers each willing to pay 1543.0 p (that's 1543 British pence, or £15.43) per share. Therefore the current bid price for this instrument is 1543.0. The first buyer wants 175 shares, the next, 300, and so on. The total volume that is demanded at 1543.0p is 2435 shares. This information is summarized on the yellow strip: 5 buyers, total volume of 2435, at 1543.0. These are all buyers who want to buy right now and the exchange will make the trade happen immediately if you put in a sell order for 1543.0 p or less. If you want to sell 2435 shares or fewer, you are good to go. The important thing to note is that once you sell these bidders a total of 2435 shares, then their orders are fulfilled and they will be removed from the order book. At this point, the next bidder is promoted up the book; but his price is 1542.5, 0.5 p lower than before. Absent any further changes to the order book, the bid price will decrease to 1542.5 p. This makes sense because you are selling a lot of shares so you'd expect the market price to be depressed. This information will be disseminated to the level one feed and the level one graph of the stock price will be updated. Thus if you have more than 2435 shares to sell, you cannot expect to execute your order at the bid price in one go. Of course, the more shares you are trying to get rid of, the further down the buy side you will have to go. In reality for a highly liquid stock as this, the order book receives many amendments per second and it is unlikely that your trade would make much difference. On the right hand side of the display you can see the recent trades: these are the times the trades were done (or notified to the exchange), the price of the trade, the volume and the trade type (AT means automatic trade).  GlaxoSmithKline is a highly liquid stock with many willing buyers and sellers. But some stocks are less liquid. In order to enable traders to find a counterparty at short notice, exchanges often require less liquid stocks to have market makers. A market maker places buy and sell orders simultaneously, with a spread between the two prices so that they can profit from each transaction. For instance Diurnal Group PLC has had no trades today and no quotes. It has a more complicated order book, enabling both ordinary buyers and sellers to list if they wish, but market makers are separated out at the top. Here you can see that three market makers are providing liquidity on this stock, Peel Hunt (PEEL), Numis (NUMS) and Winterflood (WINS). They have a very unpalatable spread of over 5% between their bid and offer prices. Further in each case the sum total that they are willing to trade is 3000 shares. If you have more than three thousand Dirunal Group shares to sell, you would have to wait for the market makers to come back with a new quote after you'd sold the first 3000. From your question, I am guessing that you are intending to have stoploss buy order. is the stoploss order is also a buy order ?  As you also said, you seems to limit your losses, I am again guessing that you have short position of the stock, to which you are intending to place a buy limit order and buy stoploss order (stoploss helps when when the price tanks). And also I sense that you intend to place buy limit order at the price below the market price. is that the situation?  If you place two independent orders (one limit buy and one stoploss buy). Please remember that there will be situation where two orders also get executed due to market movements. Add more details to the questions. it helps to understand the situation and others can provide a strategic solution. "Let's handle this as a ""proof of concept"" (POC); OP wants to buy 1 share of anything just to prove that they can do it before doing the months of painstaking analysis that is required before buying shares as an investment. I will also assume that the risks and costs of ownership and taxes would be included in OP's future analyses. To trade a stock you need a financed broker account and a way to place orders. Open a dealing account, NOT an options or CFD etc. account, with a broker. I chose a broker who I was confident that I could trust, others will tell you to look for brokers based on cost or other metrics. In the end you need to be happy that you can get what you want out of your broker, that is likely to include some modicum of trust since you will be keeping money with them. When you create this account they will ask for your bank account details (plus a few other details to prevent fraud, insider trading, money laundering etc.) and may also ask for a minimum deposit. Either deposit enough to cover the price of your share plus taxes and the broker's commission, plus a little extra to be on the safe side as prices move for every trade, including yours, or the minimum if it is higher. Once you have an account the broker will provide an interface through which to buy the share. This will usually either be a web interface, a phone number, or a fax number. They will also provide you with details of how their orders are structured. The simplest type of order is a ""market order"". This tells the broker that you want to buy your shares at the market price rather than specifying only to buy at a given price. After you have sent that order the broker will buy the share from the market, deduct the price plus tax and her commission from your account and credit your account with your share." "You can certainly try to do this, but it's risky and very expensive. Consider a simplified example. You buy 1000 shares of ABC at $1.00 each, with the intention of selling them all when the price reaches $1.01. Rinse and repeat, right? You might think the example above will net you a tidy $10 profit. But you have to factor in trade commissions. Most brokerages are going to charge you per trade. Fidelity for example, want $4.95 per trade; that's for both the buying and the selling. So your 1000 shares actually cost you $1004.95, and then when you sell them for $1.01 each, they take their $4.95 fee again, leaving you with a measly $1.10 in profit. Meanwhile, your entire $1000 stake was at risk of never making ANY profit - you may have been unlucky enough to buy at the stock's peak price before a slow (or even fast) decline towards eventual bankruptcy.  The other problem with this is that you need a stock that is both stable and volatile at the same time. You need the volatility to ensure the price keeps swinging between your buy and sell thresholds, over and over again. You need stability to ensure it doesn't move well away from those thresholds altogether. If it doesn't have this weird stable-volatility thing, then you are shooting yourself in the foot by not holding the stock for longer: why sell for $1.01 if it goes up to $1.10 ten minutes later? Why buy for $1.00 when it keeps dropping to $0.95 ten minutes later? Your strategy means you are always taking the smallest possible profit, for the same amount of risk. Another method might be to only trade each stock once, and hope that you never pick a loser. Perhaps look for something that has been steadily climbing in price, buy, make your tiny profit, then move on to the next company. However you still have the risk of buying something at it's peak price and being in for an awfully long wait before you can cash out (if ever). And if all that wasn't enough to put you off, brokerages have special rules for ""frequent traders"" that just make it all the more complicated. Not worth the hassle IMO." I normally just do a buy limit at the price I want to buy it at. Then it executes when it's that price or lower, but there's still a chance you might purchase some shares at a larger price. But since we're small fry and using brokerages, there's not much we can do about it. How would this trade behave IRL? I don't know how the simulation handles limit orders and bid/ask spreads to know it's feasible, but buying at 4.04 when the current ask is 8.00 seems unlikely.  That would mean that all other sell orders between 8.00 and 4.04 were fulfilled, which means that there were very few sellers or that sell pressure spiked, both of which seem unlikely. In reality, it seems more likely that your order would have sat there until the ask dropped to $4.04 (if it ever did), and then you'd have to wait until the bid rose to $7.89 in order to sell them at that price. However, that kind of swing in option prices in not unrealistic.  Options near at-the-money tend to move in price at about 50% of the change in the underlying, so if amazon suddenly dropped by $5, the option price could drop by $2.60 (from 6.66 to $4.04), and then rise back to $7.89 if the price rose $8 (which would be 1% swing and not unheard of intra-day). But it sounds like you got very lucky (or the simulation doesn't handle option trading realistically) - I've traded options in the past and have had some breaks similar to yours.  I've also had bad breaks where I lost my entire investment (the options expire out-of-the money). So it should be a very limited part of your portfolio, and probably only used for risk management (e.g. buying put options to lock in some gains but keeping some upside potential). "The two dimensions are to open the trade (creating a position) and to buy or sell (becoming long or short the option). If you already own an option, you bought it to open and then you would sell it to close. If you don't own an option, you can either buy it to open, or sell it (short it) to open. If you are already short an option, you can buy it back to close. If you sell to open covered, the point is you're creating a ""covered call"" which means you own the stock, and then sell a call. Since you own the stock, the covered call has a lot of the risk of loss removed, though it also subtracts much of the reward possible from your stock."