Why is the buy price different from the sell price of a stock? [duplicate]
When there is a difference between the two ... no trading occurs. Let's look at an example: Investor A, B, C, and D all buy/sell shares of company X. Investor A wants to sell 10 shares at $20 a share (Ask price $20 x10). Investor B wants to buy 15 shares at $10 a share (Bid price $10 x15). Since the bid price and ask price are different, no sale is made. Next Investor C comes along and wants to sell 5 shares at $14 (Ask price $14 x5). Still no sale. Investor D comes along and wants to buy 5 shares for $14 each. So a sale is finally made. At this point, the stock quote moves to $14. The ask price is $20 x10 and the bid price is $10 x15. No further trading will occur until another investor is willing to buy at $20 or sell at $10.  Another discussion of this topic is shown on this post. This is called the Ask-Bid Spread. The difference varies based on the liquidly of the asset. The more liquid or the higher the volume of trades for the asset then the smaller the spread is. The spread goes to the broker to pay for some of the cost of the trade. My guess is that when there is a higher volume of shares being traded, brokers need to take less of a fee per share out of the transaction to cover their costs. This makes the spread is smaller.  This is essentially the difference in   price between the highest price that a   buyer is willing to pay for an asset   and the lowest price for which a   seller is willing to sell it. The seller will get the bid price and the buyer will pay the ask and the broker keeps the spread. From http://www.investopedia.com/terms/b/bid-askspread.asp
A stock is only worth what someone is willing to pay for it. If it trades different values on different days, that means someone was willing to pay a higher price OR someone was willing to sell at a lower price.  There is no rule to prevent a stock from trading at $10 and then $100 the very next trade... or $1 the very next trade. (Though exchanges or regulators may halt trading, cancel trades, or impose limits on large price movements as they deem necessary, but this is beside the point I'm trying to illustrate). Asking what happens from the close of one day to the open of the next is like asking what happens from one trade to the next trade... someone simply decided to sell or pay a different price.  Nothing needs to have happened in between. "Price is decided by what shares are offered at what prices and who blinks first.  The buyer and seller are both trying to find the best offer, for their definition of best, within the constraints then have set on their bid or ask. The seller will sell to the highest bid they can get that they consider acceptable. The buyer will buy from the lowest offer they can get that they consider acceptable. The price -- and whether a sale/purchase happens at all -- depends on what other trades are still available and how long you're willing to wait for one you're happy with, and may be different on one share than another ""at the same time"" if the purchase couldn't be completed with the single best offer and had to buy from multiple offers. This may have been easier to understand in the days of open outcry pit trading, when you could see just how chaotic the process is... but it all boils down to a high-speed version of seeking the best deal in an old-fashioned marketplace where no prices are fixed and every sale requires (or at least offers the opportunity for) negotiation. ""Fred sells it five cents cheaper!"" ""Then why aren't you buying from him?"" ""He's out of stock."" ""Well, when I don't have any, my price is ten cents cheaper."" ""Maybe I won't buy today, or I'll buy elsewhere. ""Maybe I won't sell today. Or maybe someone else will pay my price. Sam looks interested..."" ""Ok, ok. I can offer two cents more."" ""Three. Sam looks really interested."" ""Two and a half, and throw in an apple for Susie."" ""Done."" And the next buyer or seller starts the whole process over again. Open outcry really is just a way of trying to shop around very, very, very fast, and electronic reconciliation speeds it up even more, but it's conceptually the same process -- either seller gets what they're asking, or they adjust and/or the buyer adjusts until they meet, or everyone agrees that there's no agreement and goes home." If you buy a stock and it goes up, you can sell it and make money. But if you buy a stock and it goes down, you can lose money. "Most of the investors who have large holdings in a particular stock have pretty good exit strategies for those positions to ensure they are getting the best price they can by selling gradually into the volume over time. Putting a single large block of stock up for sale is problematic for one simple reason: Let's say you have 100,000 shares of a stock, and for some reason you decide today is the day to sell them, take your profits, and ride off into the sunset.  So you call your broker (or log into your brokerage account) and put them up for sale.  He puts in an order somewhere, the stock is sold, and your account is credited. Seems simple, right?  Well...not so fast. Professionals - I'm keeping this simple, so please don't beat me up for it! The way stocks are bought and sold is through companies known as ""market makers"".  These are entities which sit between the markets and you (and your broker), and when you want to buy or sell a stock, most of the time the order is ultimately handled somewhere along the line by a market maker.  If you work with a large brokerage firm, sometimes they'll buy or sell your shares out of their own accounts, but that's another story. It is normal for there to be many, sometimes hundreds, of market makers who are all trading in the same equity.  The bigger the stock, the more market makers it attracts.  They all compete with each other for business, and they make their money on the spread between what they buy stock from people selling for and what they can get for it selling it to people who want it. Given that there could be hundreds of market makers on a particular stock (Google, Apple, and Microsoft are good examples of having hundreds of market makers trading in their stocks), it is very competitive.  The way the makers compete is on price.  It might surprise you to know that it is the market makers, not the markets, that decide what a stock will buy or sell for. Each market maker sets their own prices for what they'll pay to buy from sellers for, and what they'll sell it to buyers for.  This is called, respectively, the ""bid"" and the ""ask"" prices.  So, if there are hundreds of market makers then there could be hundreds of different bid and ask prices on the same stock.  The prices you see for stocks are what are called the ""best bid and best ask"" prices.  What that means is, you are being shown the highest ""bid"" price (what you can sell your shares for) and the best ""ask"" price (what you can buy those shares for) because that's what is required.  That being said, there are many other market makers on the same stock whose bid prices are lower and ask prices are higher.  Many times there will be a big clump of market makers all at the same bid/ask, or within fractions of a cent of each other, all competing for business.  Trading computers are taught to seek out the best prices and the fastest trade fills they can. The point to this very simplistic lesson is that the market makers set the prices that shares trade at.  They adjust those prices based (among other factors) on how much buying and selling volume they're seeing.  If they see a wave of sell orders coming into the system then they'll start marking down their bid prices.  This keeps them from paying too much for shares they're going to have to find a buyer for eventually, and it can sometimes slow down the pace of selling as investors and automated systems notice the price decline and decide to wait to sell.  Conversely, if market makers see a wave of buy orders coming into the system, they'll start marking their ask prices up to maximize their gains, since they're selling you shares they bought from someone else, presumably at a lower price.  But they typically adjust their prices up or down before they actually fill trades.  (sneaky, eh?) Depending on how much volume there is on the shares of the company you're selling, and depending on whether there are more buyers than sellers at the moment, your share sell order may be filled at market by a market maker with no real consequence to the share's price. If the block is large enough then it's possible it will not all sell to one market maker, or it might not all happen in one transaction or even all at the same price. This is a pretty complex subject, as you can see, and I've cut a LOT of corners and oversimplified much to keep it comprehensible.  But the short answer to your question is -- it depends. Hope this helps. Good luck!" "I think the question can be answered by realizing that whoever is buying the stock is buying it from someone who can do the same mathematics. Ask your son to imagine that everyone planned to buy the stock exactly one week before Christmas.  Would the price still be cheap?  The problem is that if everyone knows the price will go up, the people who own it already won't want to sell.  If you're buying something from someone who doesn't really want to sell it, you have to pay more to get it.  So the price goes up a week before Christmas, rather than after Christmas. But of course everyone else can figure this out too.  So they are going to buy 2 weeks before, but that means the price goes up 2 weeks before rather than 1 week.  You play this game over and over, and eventually the expected increased Christmas sales are ""priced in"".  But of course there is a chance people are setting the price based on a mistaken belief. So the winner isn't the person who buys just before the others, but rather the one who can more accurately predict what the sales will be (this is why insider trading is so tempting even if it's illegal).  The price you see right now represents what people anticipate the price will be in the future, what dividends are expected in the future, how much risk people think there is, and how that compares with other available investments." When you buy a stock, you become a partial owner of the company that the stock is for. As the company is valued at a higher or lower amount, the stock will reflect that by gaining or losing value. You still own that stock. For example, if you bought a stock for $10 per share and next week it is worth $8 dollars per share, the only loss incurred is on paper. You do not have to pay the difference (which I think is what you are asking?) and will only physically lose that money if you sell at that point. Similarly if that stock becomes worth $12, you have only gained money on paper and can only physically see it if you sell at that point. It depends to some extent on how you interpret the situation, so I think this is the general idea. Say you purchase one share at $50, and soon after, the price moves up, say, to $55. You now have an unrealized profit of $5. Now, you can either sell and realize that profit, or hold on to the position, expecting a further price appreciation. In either case, you will consider the price change from this traded price, which is $55, and not the price you actually bought at. Hence, if the price fell to $52 in the next trade, you have a loss of $3 on your previous profit of $5. This (even though your net P&L is calculated from the initial purchase price of $50), allows you to think in terms of your positions at the latest known prices. This is similar to a Markov process, in the sense that it doesn't matter which route the stock price (and your position's P&L) took to get to the current point; your decision should be based on the current/latest price level. Consider the mechanic which actually drives the 'price' of a stock. In simplest terms, the 'price' of a stock is the price at which the most recent trade occurred. ie: if the price of IBM is $100/share, that means the last time someone bought IBM stock, they paid $100. Above and below the 'spot price', are dozens/hundreds/thousands of buyers and sellers who have placed orders that no one is yet willing to match. ie: if IBM's spot price is at $100, there could still be 10,000 people willing to sell for $101 (called the 'ask' price, for the lowest price someone is currently willing to sell at), and 15,000 willing to buy for $99 (called the 'bid' price, for the highest price someone is currently willing to buy for).  Until someone is willing to buy for $101, then no one will be able to sell at $101. Until someone is willing to sell for $99, no one will be able to buy for $99. Typically orders are placed in the market at a particular limit. Meaning that those orders to buy at $99/sell at $101 are already in the 'system', and will be matched immediately as soon as someone is willing to meet the price on the other side. Now consider general market economics: high demand drives up price, and high supply drives down price. If the details above for IBM were yesterday, and today some news came out that IBM was laying off employees, imagine that another 10,000 people who held shares wanted to sell. Now there would be 20,000 sellers and only 15,000 buyers. If those new sellers were aggressive about wanting to sell, they would have to drop their price to $99, to match the highest buyers in the market. Put together, this means that as more sellers enter the market, supply of shares increases, driving down price. Conversely, as more buyers enter the market, demand for shares increases, driving up share price. As a result of the above, you can say that (all else being equal) if price for a stock goes up, there were more buyers that day, and if price goes down, there were more sellers that day. On the face of it, that is not necessarily true, because you could have the same number of buyers and sellers, one side could have simply decreased/increased their acceptable price to match the other side. "The market capitalization of a stock is the number of shares outstanding (of each stock class), times the price of last trade (of each stock class). In a liquid market (where there are lots of buyers and sellers at all price points), this represents the price that is between what people are bidding for the stock and what people are asking for the stock.  If you offer any small amount more than the last price, there will be a seller, and if you ask any small amount less than the last price, there will be a buyer, at least for a small amount of stock. Thus, in a liquid market, everyone who owns the stock doesn't want to sell at least some of their stock for a bit less than the last trade price, and everyone who doesn't have the stock doesn't want to buy some of the stock for a bit more than the last trade price. With those assumptions, and a low-friction trading environment, we can say that the last trade value is a good midpoint of what people think one share is worth.  If we then multiply it by the number of shares, we get an approximation of what the company is worth. In no way, shape or form does it not mean that there is 32 billion more invested in the company, or even used to purchase stock. There are situations where a 32 billion market cap swing could mean 32 billion more money was invested in the company: the company issues a pile of new shares, and takes in the resulting money.  People are completely neutral about this gathering in of cash in exchange for dilluting shares.  So the share price remains unchanged, the company gains 32 billion dollars, and there are now more shares outstanding. Now, in some sense, there is zero dollars currently invested in a stock; when you buy a stock, you no longer have the money, and the money goes to the person who no longer has the stock. The issue here is the use of the continuous tense of ""invested in""; the investment was made at some point, but the money doesn't really stay in this continuous state of being.  Unless you consider the investment liquid, and the option to take money out being implicit, it being a continuous action doesn't make much sense. Sometimes the money is invested in the company, when the company causes stocks to come into being and sells them. The owners of stocks has invested money in stocks in that they spent that money to buy the stocks, but the total sum of money ever spent on stocks for a given company is not really a useful value. The market capitalization is an approximation, which under the efficient market hypothesis (that markets find the correct price for things nearly instantly) is reasonably accurate, of the value the company has collectively to its shareholders.  The efficient market hypothesis isn't accurate, but it is an acceptable rule of thumb. Now, this value -- market capitalization -- is arguably not the total value of a company: other stakeholders include bond holders, labour, management, various contract counter-parties, government and customers.  Some companies are structured so that almost all value is captured not by the stock owners, but by contract counter-parties (this is sometimes used for hiding assets or debts). But for most large publically traded companies, it (in theory) shouldn't be far off." The last column in the source data is volume (the number of stocks that was exchanged during the day), and it also has a value of zero for that day, meaning that nobody bought or sold the stocks on that day. And since the prices are prices of transactions (the first and the last one on a particular day, and the ones with the highest/lowest price), the prices cannot be established, and are irrelevant as there was not a single transaction on that day. Only the close price is assumed equal to its previous day counterpart because this is the most important value serving as a basis to determine the daily price change (and we assume no change in this case). Continuous-line charts also use this single value. Bar and candle charts usually display a blank space for a day where no trade occurred. "Check your math... ""two stocks, both with a P/E of 2 trading at $40 per share lets say, and one has an EPS of 5 whereas the other has an EPS of 10 is the latter a better purchase?"" If a stock has P/E of 2 and  price of $40 it has an EPS of $20. Not $10. Not $5." "Feel free to educate man. Everything I can find says the same thing.  [Investopedia](http://www.investopedia.com/ask/answers/100314/what-are-key-factors-cause-market-go-and-down.asp)  &gt;If there are a greater number of buyers than sellers (more demand), the buyers bid up the prices of the stocks to entice sellers to get rid of them. Conversely, a larger number of sellers bids down the price of stocks hoping to entice buyers to purchase.  Yes, if a company is performing well, you might find that more people want to buy then sale.  That would cause it to go up.  But if no one wants to buy, it doesn't matter how well the company is doing.  I mean really, how would that work?  Someone in the company notices they had more sales today then yesterday, email someone on wallstreet and they just mouse wheel the stock price up to something higher?  Say the stock is $1.00 right now.  But the lowest buy order is $.90.  and the highest sale order is $1.10.  (I guess there is some math there making is $1.)  As soon as someone says, yeah.  I'll sale at 90 cents, it'll go down.  If someone says yeah, I'll buy at $1.10 it'll go up.    I'm sure there is more to it than that.  But everything I can find.  It 100% has to have people more people wanting to buy then sale for it to go up.  If more want to sale then buy, it'll go down.   But hey, if this is way off base.  Go ahead and fill me in.  I'm open to CMV.  This was all found after a short amount of time researching [""What makes stock prices go up?""](https://www.google.com/search?q=What+makes+stock+prices+go+up%3F&amp;oq=What+makes+stock+prices+go+up%3F&amp;gs_l=psy-ab.3..0i71k1l4.43421.43421.0.43882.0.0.0.0.0.0.0.0..0.0....0...1.1.64.psy-ab..0.0.0....0.6Crfejzb3XY)" "Both prices are quotes on a single share of stock. The bid price is what buyers are willing to pay for it. The ask price is what sellers are willing to take for it. If you are selling a stock, you are going to get the bid price, if you are buying a stock you are going to get the ask price. The difference (or ""spread"") goes to the broker/specialist that handles the transaction." Yes, you will come out ahead slightly by putting the money in the savings account, then paying off your mortgage later.  However, we don't know what will happen to these interest rates after 1 year. If you put the £300 per month into the savings account for a year, then put the money into you mortgage, you will save about £78 for the year over just putting the money toward your mortgage in the first place.  For me, I'm more concerned about longer term strategy. What happens to your mortgage rate after 2 years? What happens to your savings account rate after 1 year? The mortgage rate likely goes up and the savings account rate likely goes down, making the savings of this strategy even less after the first year. Instead, you may want to put this £300 per month toward retirement investments (assuming you have no other debt), which should, over the long term, earn more than the savings account. You'll have much more flexibility and peace of mind if your expenses are based on your current income and that income increases in the future. It's great that you aren't comfortable with spending more, you don't want to end up in the position you just removed yourself from.  That said, you don't just ignore planned income altogether. Personally, my wife and I feel best knowing that I have the essentials covered with my income, and that her income primarily helps us put away more for retirement, home renovations, and vacations, because she likely won't work for a long while if we have kids. How you plan depends on your wife's career aspirations and prospects, if your wife has high income potential and you don't plan to buy until after she resumes work, then it may suit you to plan on her income too. You'll have to balance the certainty and amount of her income with your goals.  If you're trying to make up ground on savings/retirement, then a less expensive house seems wise anyway. It's a much easier problem to decide what to do with excess funds than feeling trapped/stressed by a high mortgage payment.