What's the difference between Buy and Sell price on the stock exchange [duplicate]
The same as when you are buying a car. If a dealer quotes 10k and you quote 8k. 8k is the buy price and 10k is the sell price.  Somebody might quote 8.5k and another dealer might quote 9.5k. The the new price that you see on your screen is 8.5k(Best buy price) and 9.5k(Best sell price). When the buyer and seller agree to an amount, the car(In your case stock) is traded. The Bid price is simply the highest buy price currently being offered and the Ask price simply the lowest sell price being offered. The list of Bid and Ask prices is called the market depth. When the Bid and Ask prices match then a sale goes through. When looking to sell you would generally look at both the Bid and Ask prices. As a seller you want to be matched with the Bid price to get a sale, but you also need to check the current list of Ask prices. If the price you want to sell at is too high you will be placed down the Ask price list, and unless the price moves up to match your sell price you will not end up selling. On the other-hand, if your price to sell is too low and in fact much lower than the current lowest sell price you may get a quick sale but maybe at a lower price than you could have gotten. Similarly, when looking to buy, you would generally also look at both the Bid and Ask prices. As a buyer you want to be matched with the Ask price to get a sale, but you also need to check the current list of Bid prices. If the price you want to buy at is too low you will be placed down the Bid price list, and unless the price moves down to match your buy price you will no end up buying. On the other-hand, if your price to buy is too high and in fact much higher than the current highest buy price you may get a quick purchase but maybe at a higher price than you could have gotten. So, whether buying or selling, it is important to look at and consider both the Bid and Ask prices in the market depth. To add to @Victor 's answer; if you are entering a market order, and not a limit order (where you set the price you want to buy or sell at), then the Ask price is what you can expect to pay to purchase shares of stock in a long position and the Bid price is what you can expect to receive when you sell stock you own in a long position. This is copying my own answer to another question, but this is definitely relevant for you: A bid is an offer to buy something on an order book, so for example you may post an offer to buy one share, at $5. An ask is an offer to sell something on an order book, at a set price. For example you may post an offer to sell shares at $6. A trade happens when there are bids/asks that overlap each other, or are at the same price, so there is always a spread of at least one of the smallest currency unit the exchange allows. Betting that the price of an asset will go down, traditionally by borrowing some of that asset and then selling it, hoping to buy it back at a lower price and pocket the difference (minus interest). Going long, as you may have guessed, is the opposite of going short. Instead of betting that the price will go down, you buy shares in the hope that the price will go up. So, let's say as per your example you borrow 100 shares of company 'X', expecting the price of them to go down. You take your shares to the market and sell them - you make a market sell order (a market 'ask'). This matches against a bid and you receive a price of $5 per share. Now, let's pretend that you change your mind and you think the price is going to go up, you instantly regret your decision. In order to pay back the shares, you now need to buy back your shares as $6 - which is the price off the ask offers on the order book. Similarly, the same is true in the reverse if you are going long. Because of this spread, you have lost money. You sold at a low price and bought at a high price, meaning it costs you more money to repay your borrowed shares. So, when you are shorting you need the spread to be as tight as possible.
"In general, I think you're conflating a lot of ideas.   The stock market is not like a supermarket.  With the exception of a direct issue, you're not buying your shares from the company or from the New York Stock Exchange you're buying from an owner of stock, Joe, Sally, a pension fund, a hedge fund, etc; it's not sitting on a shelf at the stock market. When you buy an Apple stock you don't own $10 of Apple, you own 1/5,480,000,000th of Apple because Apple has 5,480,000,000 shares outstanding.  When a the board gets together to vote on and approve a dividend the approved dividend is then divided by 5.48 billion to determine how much each owner receives.  The company doesn't pay dividends out to owners from a pot of money it received from new owners; it sold iPhones at a profit and is sending a portion of that profit to the owners of the company.   ""When you buy stock, it is claimed that you own a small portion of the   company. This statement has no backing, as you cannot exchange your   stock for the company's assets."" The statement does have backing.  It's backed by the US Judicial system.  But there's a difference between owning a company and owning the assets of the company.  You own 1/5,480,000,000 of the company and the company owns the company's assets.  Nevermind how disruptive it would be if any shareholder could unilaterally decide to sell a company's buildings or other assets. This is not a ponzi scheme because when you buy or sell your Apple stock, it has no impact on Apple, you're simply transacting with another random shareholder (barring a share-repurchase or direct issue).  Apple doesn't receive the proceeds of your private transaction, you do. As far as value goes, yes the stock market provides tons of value and is a staple of capitalism.  The stock market provides an avenue of financing for companies.  Rather than taking a loan, a company's board can choose to relinquish some control and take on additional owners who will share in the spoils of the enterprise.   Additionally, the exchanges deliver value via an unbelievable level of liquidity.  You don't have to go seek out Joe or Sally when you want to sell your Apple stock.  You don't need to put your shares on Craigslist in the hope of finding a buyer.  You don't have to negotiate a price with someone who knows you want to sell.  You just place an order at an exchange and you're aligned with a buyer.   Also understand that anything can move up or down in value without any money actually changing hands.  Say you get your hands on a pair of shoes (or whatever), they're hot on the market, very rare and sought after.  You think you can sell them for $1,000. On tonight's news it turns out that the leather is actually from humans and the CEO of the company is being indicted, the company is falling apart, etc.  Your shoes just went from $1,000 to $0 with no money changing hands (or from $1,000 to $100,000 depending on how cynical you are)." If a company's shares trade in multiple exchanges, the prices in every exchange are very near to each other, otherwise you could earn money by doing arbitrage deals (buying in one, selling in the other) - and people do that once it becomes worth it. Which stock exchange you use is more a convenience for the buyer/seller - many investment banks offer only something local/near, and you have to go to specific investment banks to use other exchanges. For example, in Germany, it is easy to deal in Frankfurt, but if you want to trade at the the NASDAQ, you have to run around and find a bank that offers it, and you probably have to pay extra for it. In the USA, most investment banks offer NASDAQ, but if you want to trade in Frankfurt, you will have run around for an international company that offers that. As a stock owner/buyer, you can sell/buy your shares on any stock exchange where the company is listed (again, assuming your investment broker supports it). So you can buy in Frankfurt and sell in Tokyo seconds later, as nothing needs to be physically moved. Companies that are listed in multiple stock exchangs are typically large, and offer this to make trading their shares easier for a larger part of the world. Considering your 'theoretical buy all shares' - the shares are not located in the exchanges, they are in the hands of the owners, and not all are for sale, for various reasons. The owners decide if and when they want them offered for sale, and they also decide which stock exchange they offer them on; so you would need to go to all exchanges to buy them all. However, if you raise your offer price in one exchange only slightly, someone will see the arbitrage and buy them in the other locations and offer them to you in your stock exchange; in other words, for a small fee the shares will come to you. But again, most shares are typically not for sale. It's the same as trying to buy all Chevy Tahoes - even if you had the money, most owners wouldn't know or care about you. You would have to go around and contact every single one and convince them to sell. Why is the stock trading at only $5 per share? The share price is the perceived value of the company by people buying and selling the stock. Not the actual value of the company and all its assets. Generally if the company is not doing well, there is a perceived risk that it will burn out the money fast. There is a difference between its signed conditional sale and will get money and has got money. So in short, it's trading at $5 a share because the market doesn't feel like it's worth $12 per share. Quite a few believe there could be issues faced; i.e. it may not make the $12, or there will be additional obligations, i.e. employees may demand more layoff compensation, etc. or the distribution may take few years due to regulatory and legal hurdles. The only problem is the stock exchange states if the company has no core business, the stock will be suspended soon (hopefully they can release the $12 per share first). What will happen if I hold shares in the company, the stock gets suspended, and its sitting on $12 per share? Can it still distribute it out? Every country and stock markets have laid out procedures for de-listing a company and closing a company. The company can give $10 as say dividends and remaining later; or as part of the closure process, the company will distribute the balance among shareholders. This would be a long drawn process. "A market sell order will be filled at the highest current ""bid"" price. For a reasonably liquid stock, there will be several buy orders in line, and the highest bid must be filled first, so there should a very short time between when you place the order and when it is filled.   What could happen is what's called front running. That's when the broker places their own order in front of yours to fulfill the current bid, selling their own stock at the slightly higher price, causing your sale to be filled at a lower price.  This is not only unethical but illegal as well. It is not something you should be concerned about with a large broker.   You should only place a market order when you don't care about minute differences between the current ask and your execution price, but want to guarantee order execution. If you absolutely have to sell at a minimum price, then a limit order is more appropriate, but you run the risk that your limit will not be reached and your order will not be filled. So the risk is a tradeoff between a guaranteed price and a guaranteed execution." In a perfect market, share prices are by definition a perfect reflection of the true value of a share. Hence, you always get $10 for a share that's worth that much. In reality, the market is imperfect. Prices are somewhat of an average of all different estimates, and there's a cost-of-trading margin between sales and buy prices. Hence, in a perfect market it doesn't matter whether you have a stop loss order at $9.00. That just trades your stock worth $9 for cash worth the same $9. In an imperfect market, that trade nets you less. Furthermore, is risk a linear function of money? Perhaps not, if you bought on margin, need to lend extra and your interest rate increases with the extra credit demand. The difference between the two numbers is that the market size of a particular product is expressed as an annual number ($10 million per year, in your example).  The market cap of a stock, on the other hand, is a long-term valuation of the company. The stock price is what people think a company is worth, this is made up of When a company pays out a dividend the money in the company’s bank account reduces, therefore the value of the company reduces.    When a company says they are going to pay a larger dividend than expected, we start to expect they are going to make more profit next year as well. So stock price tends to go up when a company says it is increasing the dividend, but down on the day then money leaves the companies bank account.   There is normally many months between the two events. 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.