Supply & Demand - How Price Changes, Buy Orders vs Sell Orders [duplicate]
"For every buyer there is a seller. That rule refers to actual (historical) trades. It doesn't apply to ""wannabees."" Suppose there are buyers for 2,000 shares and sellers for only 1,000 at a given price, P. Some of those buyers will raise their ""bid"" (the indication of the price they are willing to pay) above P so that the sellers of the 1000 shares will fill their orders first  (""sold to the highest bidder""). The ones that don't do this will (probably) not get their orders filled. Suppose there are more sellers than buyers. Then some sellers will lower their ""offer"" price to attract buyers (and some sellers probably won't). At a low enough price, there will likely be a ""match"" between the total number of shares on sale, and shares on purchase orders." Yes for every order there is a buyer and seller. But overall there are multiple buyers and multiple sellers. So every trade is at a different price and this price is agreed by both buyer and seller. Related question will help you understand this better. How do exchanges match limit orders? That is mostly true, in most situations when there are more buy orders than sell orders (higher buy volume orders than sell volume orders), the price will generally move upwards and vice versa, when there are more sell orders than buy orders (higher sell volume orders than buy volume orders), the price will generally move downwards. Note that this does not always happen, but usually it does. You are also correct that for a trade to take place a buyer has to be matched with a seller (or the buy volume matched with the sell volume). But not all orders get executed as trades. Say there are 50 buy orders in the order book with a total volume of 100,000 shares and the highest buy order is currently at $10.00. On the other side there are only 10 sell orders in the order book with total volume of 10,000 shares and the lowest sell order is currently $10.05. At the moment there won't be a trade unless a new buyer or seller enters the market to match the opposing side, or an existing order gets amended upper or lower to match the opposing side. With more demand than supply in the order books what will be the most likely direction that this stock moves in? Most likely the price will move upwards. If a new buyer sees the price moving higher and then looks at the market depth, they would most likely place an order closer to the lowest sell order than the current highest buy order, say $10.01, to be first in line in case a market sell order is placed on the market. As new buy orders enter the market it drives the price higher and higher until the buy orders dry up.
"As @ApplePie pointed out in their answer, at any given time there is a finite amount of stock available in a company. One subtlety you may be missing is that there is always a price associated with an offer to buy shares. That is, you don't put in an order simply to buy 1 share of ABC, you put in an order to buy 1 share of ABC for $10. If no one is willing to sell a share of ABC for $10, then your order will go unfilled. This happens millions of times a day as traders try to figure the cheapest price they can get for a stock. Practically speaking, there is always a price at which people are willing to sell their shares. You can put in a market order for 1 share of ABC, which says essentially ""I want one share of ABC, and I will pay whatever the market deems to be the price"". Your broker will find you 1 share, but you may be very unhappy about the price you have to pay! While it's very rare for a market to have nobody willing to sell at any price, it occasionally happens that no one is willing to buy at any price. This causes a market crash, as in the 2007-2008 financial crisis, when suddenly everyone became very suspicious of how much debt the major banks actually held, and for a few days, very few traders were willing to buy bank stocks at any price." "You will almost certainly be able to sell 10,000 shares at once. The question is a matter of price. If you sell ""at market"" then you may get a lower price for each ""batch"" of the stock sold (one person buys 50, another buys 200, another buys 1000 etc) at varying prices. Will you be able to execute a single order to sell them all at the same price at the same time? Nobody can say, and it's not really a function of the company size. The exchange has what's called ""open interest"" which roughly correlates to how many people have active orders in at a given price. This number is constantly changing alongside the bid and ask (particularly for active stocks). So let's say you have 10,000 shares and you want to sell them for $100 each. What you need is at least 10,000 in open interest at $100 bid to execute. By contrast let's say you issue a limit order at $100 for 10,000 shares. Your ask will stay outstanding at that price and you'll be filled at that price if there are enough buyers. I you have a limit sell order at $100 for 10,000 shares the strike price of the stock cannot go to $100.01 until all of your sell orders are filled." The principle of demand-supply law will not work if spoofing (or layering, fake order) is implemented. However, spoofing stocks is an illegal criminal practice  monitored by SEC. In stock market, aggressive buyer are willing to pay for a higher ask price pushing the price higher even if ask size is considerably larger than bid size, especially when high growth potential with time is expected. Larger bids may attract more buyers, further perpetuating a price increase (positive pile-on effect). Aggressive sellers are willing to accept a lower bid price pushing the price lower even if ask size is considerably smaller than bid size, when a negative situation is expected. Larger asks may attract more sellers, further perpetuating a price fall (negative pile-on effect).  Moreover, seller and buyers considers not only price but also size of shares in their decision-making process, along with marker order and/or limit order. Unlike limit order, market order is not recorded in bid/ask size. Market order, but not limit order, immediately affects the price direction. Thus, ask/bid sizes alone do not give enough information on price direction. If stocks are being sold continuously at the bid price, this could be the beginning of a downward trend; if stocks are being sold continuously at the ask price, this could be the beginning of a upward trend.  This is because ask price is always higher than bid price. In all the cases, both buyers and sellers hope to make a profit in a long-term and short-term view "Yes and no. First off, commodity prices reflect the cost of a good about 3 steps back in the retail supply chain; the agreed-upon price for the raw foodstuff between farmers/ranchers and manufacturers. Your grocer may carry bags of whole grain wheat, but that's certainly not all he carries that contains it. Same for corn, rice and other staple grains, as well as for fruits and vegetables, herbs (yes, you can buy basil by the ton on the CME), meats, various sugars, etc. So, a long-term sustained change in prices of a commodity foodstuff will eventually affect the real cost to you to buy things they're made from. However, in the short term, the retail supply chain will generally act as a buffer between these prices and the ones you see on the store shelf. Consumers don't like price increases, especially of necessities like food. When food costs go up, consumers can and will very quickly change their spending habits, buying cheaper options to get their needed calories. That makes manufacturers nervous; consumers not buying their product is a worse scenario than consumers buying their product at a reduced gain or even at a loss. So, manufacturers, and suppliers and retailers, will all absorb as much as they can of the cost of a commodities increase before beginning to pass it on to consumers. On the flip side, while consumers like price drops, they don't notice them as much as price increases. So, the supply chain will also absorb a fall in commodity prices by resisting price reductions in the consumer goods, as long as they can get away with it (which is usually longer than the price reduction actually lasts). The net effect is that processed food prices typically follow the gentle upward climb of long-term inflation, and only rarely do you see drastic price increases or decreases. Where this model breaks down a little bit is in highly perishable foodstuffs, especially seasonal or ""wild-managed"" foods; fruits and vegetables, seafood, etc. The limited time in which the stuff can be sold makes the process of getting a fish out of the ocean and a fruit off the tree and into your grocery store much more market-driven; the producers, suppliers and grocers are all in constant contact over what's available and how much they can get for what price. The prices therefore are typically a lower markup (unlike highly processed grain-based foods, there's not much added value to be marked up between the apple farmer picking the fruit and the grocer putting it on display), but also much more volatile; if there's a bumper crop of fruit, the farmer has to unload it all or it goes to waste, while similarly if an early freeze decimated the apple crop, the suppliers can't just get some of last year's bumper crop out of storage; they fight with everyone else for what little made it to market. Farmers will sometimes intentionally let excess crop spoil in order to maintain a minimum price for what they sell (the rest can at least be composted and used for fertilizer, saving them some money on maintenance), but there's no silver bullet for a shortage. This is why a lot of these foods, especially seafood, are considered luxury items; they're not stable enough for everyone to get as much as they want whenever they want, unlike staple grains." "Exchange A has 100 shares of a stock at $10, the next 100 shares cost $10.01. Exchange B has the same pricing structure.  A fund manager wants to buy 200 shares of the stock, and decides that buying 100 shares at $10 from each exchange will be cheaper than staying in one exchange and paying $10.01 for the second half of his order.  The manager places two separate orders. Let's say the first order reaches exchange A, and the trade executes at $10. Traders (algorithms) on exchange B see this happen, and adjust their price up to $10.01 accordingly. Now, when the manager's order reaches exchange B, there will no longer be any shares trading at $10.  Some people say that this is front running, but if the manager only wanted 100 shares, the price would have still shifted. Some say this creates a more efficient market with tighter spreads due to the decreased risk to the market maker, but it also means the aggregate bid-ask offers across multiple exchanges are not necessarily accurate, creating a ""false liquidity"". You can decide for yourself whether or not this is a good thing." "- In a quote driven market, must every investor trade with a market        maker? In other words, two parties that are both not market makers        cannot trade between themselves directly? In a way yes, all trades go through a market maker but those trades can be orders put in place by a ""person"" IE: you, or me. - Does a quote driven market only display the ""best"" bid and ask        prices proposed by the market makers? In other words, only the        highest bid price among all the market makers is displayed, and        other lower bid prices by other market makers are not? Similarly,        only the lowest ask price over all market makers is displayed, and        other higher ask prices by other market makers are not? No, you can see other lower bid and higher ask prices. - In a order-driven market, is it meaningful to talk about ""the current stock price"", which is the price of last transaction? Well that's kind of an opinion. Information is information so it won't be bad to know it. Personally I would say the bid and ask price is more important. However in the real world these prices are changing constantly and quickly so realistically it is easier to keep track of the quote price and most likely the bid/ask spread is small and the quote will fall in between. The less liquid a security is the more important the bid/ask is. -- This goes for all market types. - For a specific asset, will there be several transactions happened at    the same time but with different prices? Today with electronic markets, trades can happen so quickly it's difficult to say. In the US stock market trades happen one at a time but there is no set time limit between each trade. So within 1 second you can have a trade be $50 or $50.04. However it will only go to $50.04 when the lower ask prices have been exhausted.   - Does an order driven market have market makers?  By definition, no. - What are some examples of quote driven and order driven financial markets, in which investors are commonly trading stocks and derivatives, especially in U.S.? Quote driven market: Bond market, Forex. Order driven market: NYSE comes from an order driven market but now would be better classified as a ""hybird market"" Conclusion: If you are asking in order to better understand today's stock markets then these old definitions of Quote market or Order market may not work. The big markets in the real world are neither. (IE: Nasdaq, NYSE...) The NYSE and Nasdaq are better classified as a ""hybird market"" as they use more then a single tactic from both market types to insure market liquidity, and transparency. Markets these days are strongly electronic, fast, and fairly liquid in most cases. Here are some resources to better understand these markets: An Introduction To Securities Markets The NYSE And Nasdaq: How They Work Understanding Order Execution" Please refer to this question to understand the basics of how an order is matched. How do exchanges match limit orders?  Now most of the times even Block orders follow the same matching criteria. I think you are assuming that for every large buy order there is a matching large sell order. This is not true.     So on the Buy side at various point in times there were Buy Orders, with Single order more than 10,000 shares. On the sell side to fulfil these orders there may or may not be a single order of 10,000. More often there will be quite a few smaller orders or 500, 1000 or whatever amount that are present in the queue based on the amount & time sort order or even partially matching out of a sell order of 10,000 ... Similarly when there is a large sell order of more than 10,000 , these may not have got filled in by a large buy order but by smaller buy orders etc ...   So if you average out the amounts on the buy side and the sell side there would definately be a difference. The analysis of this difference is as indicated in your question, buy price is more than sell price and hence people are bullish ... Many of the Bitcoin exchanges mimic stock exchanges, though they're much more rudimentary offering only simple buy/sell/cancel orders.  It's fairly normal for retail stock brokerage accounts to allow other sorts of more complex orders, where once a certain criteria is met, (the price falls below some $ threshold, or has a movement greater than some %) then your order is executed.  The space between the current buy order and the current sell order is the bid/ask spread, it's not really about timing.  Person X will buy at $100, person Y will sell at $102.  If both had a price set at $101, they would just transact.  Both parties think they can do a little bit better than the current offer.  The width of the bid/ask spread is not universal by any means.  The current highest buy order and the current lowest sell order, are both the current price.  The current quoted market price is generally the price of the last transaction, whether it's buy or sell.