In a buy order with a trigger, will I pay the current ask or the buy price in the order?
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 think that if the price does not go very far up, then your order will open on 101, because you are setting a limit order, if suddenly the price goes up very quickly or with a gep even, then you may not be given a position. But this is with a limit order and it is better to check with the broker. There are also warrants in which you can adjust the price range, for example, from 101 to 103, and at a sharp price jump, it is possible for you and would not give a position at a price of 101, but perhaps 103 would get.
"Alrighty.  So your question is, how confident are people that FB stock will close above a certain price at a certain time.  A ""call"" option contract allows you to buy shares in the future at a certain price.  FB calls are available for March of 2013.  The number in the ""strike"" column is the price you can buy FB stock at on the given date. Let's take the ""33.00"" strike.  This allows you to buy FB shares at $33 each next March.  If at that time it turns out they're worth $50 each, you can buy them at $33, then immediately sell them on the open market for $50, making money.  The person selling you the option knows that there's a chance the price will be above $33 in March, so he's going to charge you a few bucks to cover that possibility.  In this case, he's charging you $5.30 (as of me writing this).  So, you can have the option to buy FB shares at $33 each for $5.30.  This means the guy selling you the option is reasonably confident that in March, FB stock will be at or under $38.50, otherwise he'd lose money when you exercised the option.    Therefore, $38.50 is the option market's best guess as to the highest FB stock will be going for in March." One broker told me that I have to simply read the ask size and the bid size, seeing what the market makers are offering. This implies that my order would have to match that price exactly, which is unfortunate because options contract spreads can be WIDE. Also, if my planned position size is larger than the best bid/best ask, then I should break up the order, which is also unfortunate because most brokers charge a lot for options orders. Think of all the limit orders waiting in line, first organized by price, and then by the time the order was placed (earlier orders are closer to the front of the line).  In order for your buy order to trade, there must be no other limit orders of 10.01 or higher, or the sellers order would have matched with them instead. So once your order is filled, the price is 10.00, even if just for a millisecond, because there was a trade at 10.00, even though the price might go right back up after the trade. "Re: A trader when buying needs to buy at the ask price and when selling needs to sell   at the bid price. So how can a trade happen 'in between' the bid and ask? Saying the trade can happen ""in between"" the bid & ask is simplistic.  There is a time dimension to the market.  It's more accurate to say that an order can be placed ""in between"" the current best bid & ask (observed at time T=0), thus establishing a new level for one or the other of those quoted prices (observed at time T>0). If you enter a market order to buy (or sell), then yes, you'll generally be accepting the current best ask (or best bid) with your order, because that's what a market order says to do: Accept the current best market price being offered for your kind of transaction.  Of course, prices may move much faster than your observation of the price and the time it takes to process your order – you're far from being the only participant. Market orders aside, you are free to name your own price above or below the current best bid & ask, respectively. ... then one could say that you are placing an order ""in between"" the bid and ask at the time your order is placed.  However – and this is key – you are also moving one or the other of those quoted prices in the process of placing your above-bid buy order or your below-ask sell order. Then, only if somebody else in the market chooses to accept your new ask (or bid) does your intended transaction take place. And that transaction takes place at the new ask (or bid) price, not the old one that was current when you entered your order. Read more about bid & ask prices at this other question: (p.s. FWIW, I don't necessarily agree with the assertion from the article you quoted, i.e.: ""By looking for trades that take place in between the bid and ask, you can tell when a strong trend is about to come to an end.""  I would say: Maybe, perhaps, but maybe not.)" You should check with your broker. I asked my broker a similar question just 2 weeks ago. With their market orders they will be filled within 3 points from the current market bid/ask. If there is any remaining it will be placed as a limit order at 3 points away from the bid/ask price. For example, if the current ask is 100 @ $1.00 followed by 500 @ $1.01, 300 @ $1.02 and 100 @ $1.03; if you were to place a buy market order for 1000 shares you would get 100 filled at $1.00, 500 filled at $1.01, 300 filled at $1.02 and 100 filled at $1.03.  If, on the other hand, you were to place a buy market order for 2000 shares you would get 100 filled at $1.00, 500 filled at $1.01, 300 filled at $1.02 and 100 filled at $1.03, with the remaining 1000 of your order being placed as a limit order at $1.03. Again, check with your broker, as they may be different in how they treat their market orders. "I look for buying a call option only at the money, but first understand the background above: Let's suppose X stock is being traded by $10.00 and it's January The call option is being traded by $0.20 with strike $11.00 for February. (I always look for 2% prize or more) I buy 100 stocks by $10.00 each and sell the option, earning $0.20 for each X stock. I will have to deliver my stocks by $11.00 (strike value agreed). No problem for me here, I took the prize plus the gain of $1.00. (continuing from item 3) I still can sell the option for the next month with strike equal or higher than that I bought. For instance, I can sell a call option of strike $10.00 and it might be worth to deliver stocks by $10.00 and take the prize. (continuing from item 3) Probably, it won't be possible to sell a call option with strike at the price that I paid for the stock, but that's not a problem. At the end of the option life (in February), the strike was $11.00 but the stock's price is $8.00. I got the $0.20 as prize and my stocks are free for trade again. I'll sell the call option for March with strike $9.00 (taking around 2% of prize). Well, I don't want to sell my stocks by $9.00 and make loss, right? But I'm selling the call option anyway. Then I wait till the price of the stock gets near the strike value (almost ATM) and I ""re-buy"" the option sold (Example: [StockX]C9 where C means month = March) and sell again the call option with higher strike to April (Example [StockX]D10, where D means month = April) PS.: At item 9 there should be no loss between the action of ""re-buy"" and sell to roll-out to the next month. When re-buying it with the stock's price near the strike, option value for March (C9) will be lower than when selling it to April (D10). This isn't any rule to be followed, this is just a conservative (I think they call it hedge) way to handle options and stocks. Few free to make money according to your goals and your style. The perfect rule is the one that meet your expectation, don't take the generalized rules too serious." If you want to make sure you pay at or below a specific price per share, use a limit order. If you want to buy the stock close to the current price, but aren't price sensitive, use a market order. Market orders are typically not a great idea because if you're buying thousands or tens of thousands of shares this can mean a large swing in cost if the market suddenly changes direction. I can't say I know everything about the underlying details, but from what I understand, your limit buy adds to the bid side of open orders, and one possibility is that someone placed a market order to sell when the bid price for the stock fell to $10 which was matched to your open limit order. So using your terminology, I would say the spot bid price is what fell to $10, even if for a brief moment. Whether or not it is possible for your order to be filled when the limit buy price is deeper than the current bid price is beyond me. It may have something to do with lot sizes. If you sold bought a call option then as you stated sold it to someone else what you are doing is selling the call you bought. That leaves you with no position.  This is the case if you are talking about the same strike, same expiration. In practice, it would not work. If you put a bid in that was really out of line, even if it got filled, the exchange would reverse it.  Other than that it really depends on what the current bid/ask spread it, and what volume its trading, as well as how the market feels. Say the current bid is 11 and you put an order in with bid 11.5, it would soak up all the orders on the market up to the volume your buying. But once your order is filled the market will be determined by what the next order's bid/ask is. It might stay where you moved it too if others feels thats a fair price. But if every other order on the market is still at 11, then the price isnt gonna move.  tl;dl unless your a market maker, you could not realistically affect the price. "When you place a limit sell order of $10.00 (for a stock on an option) you are adding your order to the book.  Anyone who places a buy at-the-market or with a limit price over $10.00 will have that order immediately fulfilled through the offer you have placed on the book. On the other hand, if that other person places a buy for $8.00, then the spread will now be ""$8.00 bid, $10.00 ask"". Priority is based on first the price (all $9.99 asks will clear before $10.00) and within each bucket this is based on the time your order was submitted. This is why in bidding markets (including eBay) buying at $x.01 is way better than $x.00 and selling at $x.99 is better than $(x+1).00. Source: https://en.wikipedia.org/wiki/Order_(exchange) under ""first-come-first-served""" 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. "My broker offers the following types of sell orders: I have a strategy to sell-half of my position once the accrued value has doubled.  I take into account market price, dividends, and taxes (Both LTgain and taxes on dividends).  Once the market price exceeds the magic trigger price by 10%, I enter a ""trailing stop %"" order at 10%.  Ideally what happens is that the stock keeps going up, and the trailing stop % keeps following it, and that goes on long enough that accrued dividends end up paying for the stock.  What happens in reality is that the stock goes up some, goes down some, then the order gets cancelled because the company announces dividends or something dumb like that. THEN I get into trouble trying to figure out how to re-enter the order, maintaining the unrealized gain in the history of the trailing stop order.  I screwed up and entered the wrong type of order once and sold stock I didn't want to. Lets look at an example. a number of years ago, I bought some JNJ -- a hundred shares at 62.18.  - Accumulated dividends are 2127.75  - My spreadsheet tells me the ""double price"" is 104.54, and double + 10% is 116.16.  - So a while ago, JNJ exceeded 118.23, and I entered a Trailing Stop 10% order to sell 50 shares of JNJ.  The activation price was 106.41.  - since then, the price has gone up and down...  it reached a high of 126.07, setting the activation price at 113.45.  - Then, JNJ announced a dividend, and my broker cancelled the trailing stop order.  I've re-entered a ""Stop market"" order at 113.45.  I've also entered an alert for $126.07 -- if the alert gets triggered, I'll cancel the Market Stop and enter a new trailing stop." "EVERYONE buys at the ask price and sells at the bid price (no matter who you are). There are a few important things you need to understand. Example: EVE bid: 16.00 EVE ask: 16.25 So if your selling EVE at ""market price"" you are entering an ask equal to the highest bid ($16.00). If you buy EVE at ""market price"" you are entering a bid equal to the lowest ask price ($16.25). Its key to understand this rule: ""An order executes ONLY when both bid and ask meet. (bid = ask)."" So a market maker puts in a bid when he wants to buy but the trade only executes when an ASK price meets his BID price. When you see a quote for a stock it is the price of the last trade. So it is possible to have a quote higher or lower then both the bid and the ask." "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."