how stock market sale work?
As stock prices have declined, the net worth of people has come down. Imagine owning a million shares of a stock worth $100/share. This is worth $100,000,000. Now, if the stock is suddenly trading at $50/share then some would say you have lost $50,000,000. The value of the stock is less. The uncertainty is always there as there are differences between one day's close and another day's open possibly. The sale price is likely to be near the last trade is what is being used here. If you place a market order to sell your stock, the price may move between the time the order is placed and when it is filled. There are limit orders that could be used if you want to control the minimum price you get though you give up that the order has to be filled as otherwise people could try to sell shares for millions of dollars that wouldn't work out well.
This is a gross simplification as there are a few different ways to do this. The principle overall is the same though. To short a stock, you borrow X shares from a third party and sell them at the current price. You now owe the lender X shares but have the proceeds from the sale. If the share price falls you can buy back those shares at the new lower price, return them to the lender and pocket the difference. The risk comes when the share price goes the other way, you now owe the lender the new value of the shares, so have to find some way to cover the difference. This happened a while back when Porsche made a fortune buying shares in Volkswagen from short sellers, and the price unexpectedly rose. "The ""price"" is the price of the last transaction that actually took place. According to Motley Fool wiki: A stock price is determined by what was last paid for it. During market hours (usually weekdays from 9:30AM-4:00PM eastern), a heavily traded issue will see its price change several times per second. A stock's price is, for many purposes, considered unchanged outside of market hours. Roughly speaking, a transaction is executed when an offer to buy matches an offer to sell. These offers are listed in the Order Book for a stock (Example: GOOG at Yahoo Finance).  This is actively updated during trading hours. This lists all the currently active buy (""bid"") and sell (""ask"") orders for a stock, and looks like this:  You'll notice that the stock price (again, the last sale price) will (usually*) be between the highest bid and the lowest ask price. * Exception: When all the buy or sell prices have moved down or up, but no trades have executed yet." ELI5 - you sell something that you don't own with the expectation that it will go down, and then you buy it back when it goes down in order to lock in profit.  You are charged fees to borrow the stock from someone else who currently owns it, and you also run the risk of the market going against you by going up. "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." The stock market is no different in this respect to anything that's bought or sold. The price of a stock like many other things reflects what the seller is prepared to sell it at and what the buyer is prepared to offer for it. If those things match then a transaction can take place. The seller loses money but gains stocks they feel represent equivalent value, the reverse happens for the buyer. Take buying a house for example, did the buyer lose money when they bought a house, sure they did but they gained a house. The seller gained money but lost a house. New money is created in the sense that companies can and do make profits, those profits, together with the expected profits from future years increase the value that is put on the company. If we take something simple like a mining company then its value represents a lot of things: and numerous other lesser things too. The value of shares in the mining company will reflect all of these things. It likely rises and falls in line with the price of the raw materials it mines and those change based on the overall supply and demand for those raw materials. Stocks do have an inherent value, they are ownership of a part of a company. You own part of the asset value, profits and losses made by that company. Betting on things is different in that you've no ownership of the thing you bet on, you're only dependent on the outcome of the bet. As a general principle the stock price on the stock market is controlled by an agreement between buyers and sellers. Some initial observations on this stock So, my take on this is one/more of the following My suspicion is the latter. "Stock prices are set by bidding. In principle, a seller will say, ""I want $80."" If he can't find anyone willing to buy at that price, he'll either decide not to sell after all, or he'll lower his price. Likewise, a buyer will say, ""I'll pay $70."" If he can't find anyone willing to pay that price, he'll either decide not to buy or he'll increase his price. For most stocks there are many buyers and many sellers all the time, so there's a constant interplay. The typical small investor has VERY little control of the price. You say, ""I want to buy 10 shares of XYZ Corporation and my maximum price is $20."" If the current trending price is below $20, your broker will buy it for you. If not, he won't. You normally have some time limit on the order, so if the price falls within your range within that time period, your broker will buy. That is, your choice is basically to buy or not buy, or sell or not sell, at the current price. You have little opportunity to really negotiate a better price. If you have a significant percentage of a company's total stock, different story. In real life, most stocks are being traded constantly, so buyers and sellers both have a pretty good idea of the current price. If the last sale was ten minutes ago for $20, it's unlikely anyone's going to now bid $100. They're going to bid $20.50 or $19.25 or some such. If the last sale was for $20 and your broker really came to the floor and offered to buy for $100, I suppose someone would sell to him very quickly before he realized what an outrageous price this was. I use TD Ameritrade, and on their web site, if I give a price limit on a buy that's more than a small percentage above the last sale, they reject it as an error. I forget the exact number but they won't even accept a bid of $80 if the stock is going for $40. They might accept $41 or $42, something like that." Imagine that I own 10% of a company, and yesterday my portion was valued at $1 Million, therefore the company is valued at $10 Million.  Today the company accepts an offer to sell 1% of the company for $500 Thousand: now my portion is worth $5 Million, and company is worth $50 Million. The latest stock price sets the value of the company. If next week the news is all bad and the new investor sells their shares to somebody else for pennies on the dollar, the value of the company will drop accordingly. "Very simple. You open an account with a broker who will do the trades for you. Then you give the broker orders to buy and sell (and the money to pay for the purchases). That's it. In the old days, you would call on the phone (remember, in all the movies, ""Sell, sell!!!!""? That's how), now every decent broker has an online trading platform. If you don't want to have ""additional value"" and just trade - there are many online discount brokers (ETrade, ScotTrade, TD Ameritrade, and others) who offer pretty cheap trades and provide decent services and access to information. For more fees, you can also get advices and professional management where an investment manager will make the decisions for you (if you have several millions to invest, that is). After you open an account and login, you'll find a big green (usually) button which says ""BUY"". Stocks are traded on exchanges. For example the NYSE and the NASDAQ are the most common US exchanges (there's another one called ""pink sheets"", but its a different kind of animal), there are also stock exchanges in Europe (notably London, Frankfurt, Paris, Moscow) and Asia (notably Hong Kong, Shanghai, Tokyo). Many trading platforms (ETrade, that I use, for example) allow investing on some of those as well." If you look at a trade grid you can see how this happens. If there are enough bids to cover all shares currently on the sell side at a certain price, those shares will be bought and increased price quotes will be shown for the bids and ask. If there are enough bids to cover this price, those will get bought and higher prices will be shown and this process will repeat until the sell side has more power than the buy side. It seems like this process is going on all day long with momentum either on the upside or downside. But I think that much of this bidding and selling is automatic and is being done by large trading firms and high tech computers. I also feel that many of these bids and asks are already programmed to appear once there is a price change. So once one price gets bought, computers will put in higher bids to take over asks. It's like a virtual war between trading firms and their computers. When more money is on the buy side the stock will go up, and vice versa. I sort of feel like this high-frequency trading is detrimental to the markets and doesn't really give everyone a fair shot. Retail investors do not have the resources and knowledge in order to do this sort of high frequency trading. It also seems to go against certain free market principles in my opinion. "Being ""long"" - expecting the price to go up to make a profit - is a two step process:  1) buy 2) sell Being ""short"" - expecting the price to go down to make a profit - is a 5 step process:  1) borrow someone else's asset 2) sell their asset on the open market to somebody else a third party 3) pocket the proceeds of the sell for your own account 4) buy an identical asset for a cheaper price 5) return this identical asset to the person that let you borrow their asset if this is successful you keep the difference between 3) and 4)" The money goes to the seller.  There are a lot of behind the scenes things that happen, and some transactions are very complicated with many parties involved (evidenced by all the comments on @keshlam's perfectly reasonable high-level answer), but ultimately the money goes to the seller.  Sometimes the seller is the company.  The billions of shares that change hands each day are moving between other individuals like you and investment funds; these transactions have no direct impact on the company's financials, in general. In general stock markets are very similar to that, however, you can also put in limit orders to say that you will only buy or sell at a given price. These sit in the market for a specified length of time and will be executed when an order arrives that matches the price (or better). Traders who set limit orders are called liquidity (or price) makers as they provide liquidity (i.e. volume to be traded) to be filled later. If there is no counterparty (i.e. buyer to your seller) in the market, a market maker; a large bank or brokerage who is licensed and regulated to do so, will fill your order at some price. That price is based on how much volume (i.e. trading) there is in that stock on average. This is called average daily volume (ADV) and is calculated over varying periods of time; we use ADV30 which is the 30 day average. You can always sell stocks for whatever price you like privately but a market order does not allow you to set your price (you are a price taker) therefore that kind of order will always fill at a market price. As mentioned above limit orders will not fill until the price is hit but will stay on book as long as they aren't filled, expired or cancelled. "This is a misconception. One of the explanations is that if you buy at the ask price and want   to sell it right away, you can only sell at the bid price. This is incorrect. There are no two separate bid and ask prices. The price you buy (your ""bid"") is the same price someone else sells (their ""sell""). The same goes when you sell - the price you sell at is the price someone else buys. There's no spread with stocks. Emphasized it on purpose, because many people (especially those who gamble on stock exchange without knowing what they're doing) don't understand how the stock market works. On the stock exchange, the transaction price is the match between the bid price and the ask price. Thus, on any given transaction, bid always equals ask. There's no spread. There is spread with commodities (if you buy it directly, especially), contracts, mutual funds and other kinds of brokered transactions that go through a third party. The difference (spread) is that third party's fee for assuming part of the risk in the transaction, and is indeed added to your cost (indirectly, in the way you described). These transactions don't go directly between a seller and a buyer. For example, there's no buyer when you redeem some of your mutual fund - the fund pays you money. So the fund assumes certain risk, which is why there's a spread in the prices to invest and to redeem. Similarly with commodities: when you buy a gold bar - you buy it from a dealer, who needs to keep a stock. Thus, the dealer will not buy from you at the same price: there's a premium on sale and a discount on buy, which is a spread, to compensate the dealer for the risk of keeping a stock." Unless I am missing something subtle, nothing happens to the buyer. Suppose Alice wants to sell short 1000 shares of XYZ at $5.  She borrows the shares from Bob and sells them to Charlie.  Now Charlie actually owns the shares; they are in his account. If the stock later goes up to $10, Charlie is happy; he could sell the shares he now owns, and make a $5000 profit. Alice still has the $5000 she received from her short sale, and she owes 1000 shares to Bob.  So she's effectively $5000 in debt.  If Bob calls in the loan, she'll have to try to come up with another $5000 to buy 1000 shares at $10 on the open market.   If she can't, well, that's between her and Bob.  Maybe she goes bankrupt and Bob has to write off a loss.   But none of this has any effect on Charlie!  He got the shares he paid for, and nobody's going to take them away from him.  He has no reason to care where they came from, or what sort of complicated transactions brought them into Alice's possession.  She had them, and she sold them to him, and that's the end of the story as far as he's concerned.