What factors make someone buy or sell a stock?
"First, note that a share represents a % of ownership of a company. In addition to the right to vote in the management of the company [by voting on the board of directors, who hires the CEO, who hires the VPs, etc...], this gives you the right to all future value of the company after paying off expenses and debts. You will receive this money in two forms: dividends approved by the board of directors, and the final liquidation value if the company closes shop. There are many ways to attempt to determine the value of a company, but the basic theory is that the company is worth a cashflow stream equal to all future dividends + the liquidation value. So, the market's ""goal"" is to attempt to determine what that future cash flow stream is, and what the risk related to it is. Depending on who you talk to, a typical stock market has some degree of 'market efficiency'. Market efficiency is basically a comment about how quickly the market reacts to news. In a regulated marketplace with a high degree of information available, market efficiency should be quite high. This basically means that stock markets in developed countries have enough traders and enough news reporting that as soon as something public is known about a company, there are many, many people who take that information and attempt to predict the impact on future earnings of the company. For example, if Starbucks announces earnings that were 10% less than estimated previously, the market will quickly respond with people buying Starbucks shares lowering their price on the assumption that the total value of the Starbucks company has decreased. Most of this trading analysis is done by institutional investors. It isn't simply office workers selling shares on their break in the coffee room, it's mostly people in the finance industry who specialize in various areas for their firms, and work to quickly react to news like this. Is the market perfectly efficient? No. The psychology of trading [ie: people panicking, or reacting based on emotion instead of logic], as well as any inadequacy of information, means that not all news is perfectly acted upon immediately. However, my personal opinion is that for large markets, the market is roughly efficient enough that you can assume that you won't be able to read the newspaper and analyze stock news in a way better than the institutional investors. If a market is generally efficient, then it would be very difficult for a group of people to manipulate it, because someone else would quickly take advantage of that. For example, you suggest that some people might collectively 'short AMZN' [a company worth half a trillion dollars, so your nefarious group would need to have $5 Billion of capital just to trade 1% of the company]. If someone did that, the rest of the market would happily buy up AMZN at reduced prices, and the people who shorted it would be left holding the bag. However, when you deal with smaller items, some more likely market manipulation can occur. For example, when trading penny stocks, there are people who attempt to manipulate the stock price and then make a profitable trade afterwards. This takes advantage of the low amount of information available for tiny companies, as well as the limited number of institutional investors who pay attention to them. Effectively it attempts to manipulate people who are not very sophisticated. So, some manipulation can occur in markets with limited information, but for the most part prices are determined by the 'market consensus' on what the future profits of a company will be.  Additional example of what a share really is: Imagine your neighbor has a treasure chest on his driveway: He gathers the neighborhood together, and asks if anyone wants to buy a % of the value he will get from opening the treasure chest. Perhaps it's a glass treasure chest, and you can mostly see inside it. You see that it is mostly gold and silver, and you weigh the chest and can see that it's about 100 lbs all together. So in your head, you take the price of gold and silver, and estimate how much gold is in the chest, and how much silver is there. You estimate that the chest has roughly $1,000,000 of value inside. So, you offer to buy 10% of the chest, for $90k [you don't want to pay exactly 10% of the value of the company, because you aren't completely sure of the value; you are taking on some risk, so you want to be compensated for that risk].  Now assume all your neighbors value the chest themselves, and they come up with the same approximate value as you. So your neighbor hands out little certificates to 10 of you, and they each say ""this person has a right to 10% of the value of the treasure chest"". He then calls for a vote from all the new 'shareholders', and asks if you want to get the money back as soon as he sells the chest, or if you want him to buy a ship and try and find more chests. It seems you're all impatient, because you all vote to fully pay out the money as soon as he has it. So your neighbor collects his $900k [$90k for each 10% share, * 10], and heads to the goldsmith to sell the chest. But before he gets there, a news report comes out that the price of gold has gone up. Because you own a share of something based on the price of gold, you know that your 10% treasure chest investment has increased in value. You now believe that your 10% is worth $105k. You put a flyer up around the neighborhood, saying you will sell your share for $105k. Because other flyers are going up to sell for about $103-$106k, it seems your valuation was mostly consistent with the market.  Eventually someone driving by sees your flyer, and offers you $104k for your shares. You agree, because you want the cash now and don't want to wait for the treasure chest to be sold. Now, when the treasure chest gets sold to the goldsmith, assume it sells for $1,060,000 [turns out you underestimated the value of the company]. The person who bought your 10% share will get $106k [he gained $2k]. Your neighbor who found the chest got $900k [because he sold the shares earlier, when the value of the chest was less clear], and you got $104k, which for you was a gain of $14k above what you paid for it. This is basically what happens with shares. Buy owning a portion of the company, you have a right to get a dividend of future earnings. But, it could take a long time for you to get those earnings, and they might not be exactly what you expect. So some people do buy and sell shares to try and earn money, but the reason they are able to do that is because the shares are inherently worth something - they are worth a small % of the company and its earnings." "Stock price is determined by the buyers and sellers, correct? Correct! ""Everything is worth what its purchaser will pay for it""-Publius Syrus What causes people to buy or sell? Is it news? earnings? stock analysis and techniques? All of these things influence investors' perception of how much a stock is worth. If AMZN makes a lot of money one quarter, then the price might go up. But maybe public perception of AMZN changes because of a large scandal. This could cause the share price to decline even with the favorable earnings report. Why do these 'good' or 'bad' news make people want to buy/sell a stock? People invest to make money. If it looks like a company is going to take a turn for the worst, people will sell. If it looks like the company has a bright, cash-laden future in front of them, people will buy. News is one of the many factors people use to determine how well a company will do. Theoretically could a bunch of people short AMZN and drive down the price regardless of how well it is doing? Say investors wanted to boycott AMZN in order to drive down the cost and get some cheap shares. This is pretty silly, but say for the sake of the argument that everyone who owned AMZN decided to sell their shares and no other investor was willing to buy the shares for less than $0.01, then AMZN shares would be ""worth"" $0.01 in that aspect. That is extremely unlikely to happen, though, for two reasons:" why sell?  Because the stock no longer fits your strategy.  Or you've lost faith in the company. In our case, it's because we're taking our principal out and buying something else.  Our strategy is, basically, to sell (or offer to sell) after the we can sell and get our principal out, after taxes.  That includes dividends -- we reduce the sell price a little with every dividend collected.
You have no guarantees. The stock may last have traded at $100 (so, the market price is $100), but is currently in free-fall and nobody else will be willing to buy it for any more than $80. Or heck, maybe nobody will be willing to buy it at all, at any price. Or maybe trading on this stock will be halted. Remember, the market price is just what the stock last traded at. If you put in a 'market order', you are ordering your broker to sell at the best available current price. Assuming someone's willing to buy your stock, that means you'll sell it. But if it last traded at $100, this doesn't guarantee you'll sell at anything close to that. If I buy VUSA from one exchange, can I sell it in a different exchange, assuming my brokerage account lets me trade in both exchanges? Or is it somehow tied to the exchange I bought it from? This doesn't happen for all securities and between all stock exchanges. So that is dependent on broker and country. I checked for VUSA with Selftrade. They categorically refused allowing me to trade in VUSA in different exchanges. I can only buy and sell in same currency only, albeit sell(buy) in the same exchange where I buy(sell) from. Should be the same behaviour for all brokers for us mere mortals, if you are a bank or a millionaire than that might be a different question.  The VUSA you quote is quoted in GBP in LSE and in EUR in AEX, and the ETF has been created by an Irish entity and has an Irish ISIN.  As Chris mentioned below, happens between US and Canadian exchanges, but not sure it happens across all exchanges. You cannot deal in inter-listed stocks in LSE and NYSE. Since it's the same asset, its value should not vary across exchanges once you compensate for exchange rates, right? Yes, else it opens up itself for arbitrage (profit without any risk) which everybody wants. So even if any such instance occurs, either people will exploit it to make the arbitrage profit zero (security reflects the equilibrium price) or the profit from such transaction is so less, compared with the effort involved, that people will tend to ignore it. Anyways arbitrage profit is very difficult to garner nowadays, considering the super computers at work in the market who exploit these discrepancies, the moment they see them and bring the security right to the zero arbitrage profit point. If there's no currency risk because of #2, what other factors should I consider when choosing an exchange to trade in? Liquidity? Something else? Time difference, by the time you wake up to trade in Japan, the Japanese markets would have closed. Tax implications across multiple continents. Law of the land, providing protection to investors. Finding a broker dealing in markets you want to explore or dealing with multiple brokers. Regulatory headaches. The stock market is just like any other market, but stocks are bought and sold here. Just like you buy and sell your electronics at the electronics market, this is a place where buyers and sellers come together to buy and sell shares or stocks or equity, no matter what you call it. What are these shares?  A share is nothing but a portion of ownership of a company. Suppose a company has 100 shares issued to it, and you were sold 10 out of those, it literally means you are a 10% owner of the company. Why do companies sell shares? Companies sell shares to grow or expand. Suppose a business is manufacturing or producing and selling goods or services that are high in demand, the owners would want to take advantage of it and increase the production of his goods or services. And in order to increase production he would need money to buy land or equipment or labor, etc. Now either he could go get a loan by pledging something, or he could partner with someone who could give him money in exchange for some portion of the ownership of the company. This way, the owner gets the money to expand his business and make more profit, and the lender gets a portion of profit every time the company makes some. Now if the owner decides to sell shares rather than getting a loan, that's when the stock market comes into the picture. Why would a person want to trade stocks? First of all, please remember that stocks were never meant to be traded. You always invest in stocks. What's the difference? Trading is short term and investing is long term, in very simple language. It's the greed of humans which led to this concept of trading stocks. A person should only buy stocks if he believes in the business the company is doing and sees the potential of growth. Back to the question: a person would want to buy stocks of the company because: How does a stock market help society? Look around you for the answer to this question. Let me give you a start and I wish everyone reading this post to add at least one point to the answer. Corporations in general allow many people come together and invest in a business without fear that their investment will cause them undue liability - because shareholders are ultimately not liable for the actions of a corporation. The cornerstone North American case of how corporations add value is by allowing many investors to have put money towards the railroads that were built across America and Canada. For The stock market in particular, by making it easier to trade shares of a company once the company sells them, the number of people able to conveniently invest grows exponentially. This means that someone can buy shares in a company without needing to knock door to door in 5 years trying to find someone to sell to. Participating in the stock market creates 'liquidity', which is essentially the ease with which stocks are converted into cash. High liquidity reduces risk overall, and it means that those who want risk [because high risk often creates high reward] can buy shares, and those who want low risk [because say they are retiring and don't have a risk appetite anymore] can sell shares. "There are several reasons. First, if you sell your stock ""at any price"", you may be selling it for less than you originally bought it for.  Thus you will take a loss right at the beginning of your scheme.  If you ""rinse and repeat"", the problem only gets worse.  Every time you sell your stock, you will have to sell it at an even lower price in order to lower the price even more.  Then you buy it back and. . . just resell it an even lower price?  It should be clear that you are not making any money this way. Second, even if you don't sell it at an absolute loss, you must sell it at a relative loss in order to lower the price.  In other words, if someone will currently buy your shares for $X, and you want to lower the price, you must sell them for less than $X.  But you could have made more money by selling them for $X, since someone was already willing to buy them at that price.  In order to bring the price down significantly, you have to sell the stock for less than people currently believe it is worth, which means you're incurring a loss relative to just selling it at the market rate.  Of course, you can still make money if it goes back up again, but selling it at an extra loss this way just makes it harder to break even. Third, if you sell the stock at $X, whoever you sold it to is not going to sell it right back to you at $X, because then they would not make any money.  You could in theory buy it from someone else, but the same principle holds: if the stock price has just gone down, people who have it may be waiting for it to go back up.  This is doubly true if anyone suspects you have been trying to manipulate the stock price, because they will then suspect that the price drop is artificial and it will soon go back up. Fourth, even if someone did sell it right back to you at the price you sold it for, then what?  You now hold the stock at a lower price, but you don't gain unless it goes back up.  If it wasn't going up before until you took action, there is no reason to suppose it will go back up now.  In fact, if you had enough shares to significantly influence the price, other people may have been fooled into thinking the value is actually lower now. The basic problem is that, in order for you to buy it at a low price, someone else has to sell it at that low price.  It is easy to sell someone a stock for less than it's worth, but it will be hard to get people to sell it back to you for less than it's worth.  If you engage in deceptive practices to get people to do this, you may be guilty of securities fraud." "I used to be in research department for big financial data company.   Tell your son that there are three factors: Most people think that net sales vs. expectations is the only factor.  It might not even be the biggest.  It is simply how much money did company make.  Note that this is not how many units they sold.  For most companies they will have adjustable pricing and incentives in their sector.  For example let's talk about a new company selling Superman Kid's Bikes (with a cape the flips out when you hit a certain speed).  The company has it in Walmart at one price, Target at another, Toys R' Us even cheaper, Amazon (making more profit there), and other stores.  They are doing ""OK"" come Dec. 1 but holiday season being half way over they slash price from $100 to $80 because they have tons of inventory.  What are looking at her is how much money did they make.  Note that marketing, advertising, legal (setting up contracts) are a bit fixed. In my opinion consumer sentiment is the #1 thing for a company that sells a product.  Incredible consumer sentiment is like millions of dollars in free advertising.  So let's say Dec. 15th comes and the reviews on the Superman Bike are through the roof.  Every loves it, no major defects.  Company can't even supply the retailers now because after slashing the price it became a great buy.  A common investor might be pissed that some dummy at the company slashed the prices so they could have had a much better profit margin, but at the same time it wouldn't have led to an onslaught of sales and consumer sentiment. And the last area is product sell-off.  This doesn't apply to all product but most.  Some products will only have a technology shelf life, some will actually go bad or out of fashion, and even selling Superman bikes you want to get those to the store because the product is so big.  So ignoring making a profit can a company sell off inventory at or around cost.  If they can't, even if they made a profit, their risk factor goes up. So let's get back to Superman Bikes.  This is the only product company ABC has.  They had expected holiday sales at 100 million and profits at 40 million.  They ended up at 120 million and 44 million.   Let's say their stock was $20 before any information was gathered by the public (remember for most companies info is gathered daily now so this is rather simplistic).  So you might expect that the stock would rise to maybe $24 - to which if you were an investor is a great profit. However this company has a cult consumer following who are waiting for the Captain America Bike (shoots discs) and the Hulk Bike (turns green when you go fast).  Let's say consumer sentiment and projections base off that put next holiday sales at $250 million.  So maybe the company is worth $40 a share now.  But consumer sentiment is funny because not only does it effect future projections but it also effects perceived present value of company - which may have the stock trading at $60 a share (think earnings and companies like Google).  Having a company people feel proud owning or thinking is cool is also a indicator or share worth. I gave you a really good example of a very successful company selling Superman Bikes... There are just as many companies that have the opposite happening.  Imagine missing sales goals by a few million with bad consumer feedback and all of a sudden your company goes from $20 to $5 a share." people implicity agree to sell stocks when a company does bad But, remember, when you sell the stock of a company that, in your estimation, 'did bad', someone else had to buy; otherwise, there is no sale. The someone else who bought your shares evidently disagrees with your assessment. Did you sell because the company didn't earn a profit at all? Did it not earn a profit because it's in a dead-end business that is slowly but inevitably declining to zero? Something like Sears Holdings? Or did it not make a profit because it is in an emerging market that will possibly someday become hugely profitable? Something like Tesla, Inc.? Did you sell because the company made a profit, but it was lower than expected? Did they make a lower-than-expected profit because of lower sales? Why were the sales lower? Is the industry declining? Was the snow too heavy to send the construction crews out? Did the company make a big investment to build a new plant that will, in a few years, yield even higher sales and profits? What are the profits year-over-year? Increasing? Declining? Usually, investors are willing to pay a premium, that is more than expected, for a stock in a company with robust growth.  As you can see, the mere fact that a company reported a profit is only one of many factors that determine the price of the shares in the market. "Institutions may be buying large quantities of the stock and would want the price to go up after they are done buying all that they have to buy.  If the price jumps before they finish buying then they may not make as great a deal as they would otherwise.  Consider buying tens of thousands of shares of a company and then how does one promote that?  Also, what kind of PR system should those investment companies have to disclose whether or not they have holdings in these companies.  This is just some of the stuff you may be missing here. The ""Wall street analysts"" are the investment banks that want the companies to do business through them and thus it is a win/win relationship as the bank gets some fees for all the transactions done for the company while the company gets another cheerleader to try to play up the stock." I don't get why people insist on listening to cable tv to buy their stocks or any list. I remember one time a old lady was about to invest a good chunk of money in AOL because a broker said to do it. *face palm.*