Company stock listed in multiple exchanges?
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. It doesn't matter which exchange a share was purchased through (or if it was even purchased on an exchange at all--physical share certificates can be bought and sold outside of any exchange). A share is a share, and any share available for purchase in New York is available to be purchased in London. Buying all of a company's stock is not something that can generally be done through the stock market. The practical way to accomplish buying a company out is to purchase a controlling interest, or enough shares to have enough votes to bind the board to a specific course of action. Then vote to sell all outstanding shares to another company at a particular fixed price per share. Market capitalization is an inaccurate measure of the size of a company in the first place, but if you want to quantify it, you can take the number of outstanding shares (anywhere and everywhere) and multiply them by the price on any of the exchanges that sell it. That will give you the market capitalization in the currency that is used by whatever exchange you chose. Keep in mind that the exchanges do not hold, buy, or sell the stock - people (or funds) do.  All the exchange does is facilitate the sale of stock from one entity to another. So the shares outstanding (and market cap) for a company are set regardless of how many exchanges the stock is listed on.  The company typically indicates the number of shares outstanding in its financial statements.  I do not know if the exchange itself keeps track of shares outstanding; it may just report whatever the company publishes. So theoretically, if you wanted to buy all of the stock of a company, you could do it all in one exchange, provided that all the existing holders of the stock were willing to sell you their shares.  There are many issues with that, though, which I don't think are germane to your question. "listed simultaneously in New York, London, and maybe even some Asian markets - is this correct? If the exchanges are not connected, then in primary market the shares are listed. On other exchanges, the ""Depository Receipts"" are listed. i.e. the Company will keep say 100,000 shares with the primary stock exchange / depository. Based on this it would create new instruments ""Depository Receipts"". They can be 1:1 or whatever ratio. hypothetically, if I want to buy all of the company's stock Even if it is on one exchange, buying all stocks would trigger various regulatory aspects of Companies Act, or Stock Exchange rules. This is not simple or easy like clicking some buttons and buying everything. That is, let's say that in New York the company has listed 1000 shares, and in London only 10 shares, each worth 10 USD Market capitalization is sum of all outstanding shares into value."
For a company listed on NASDAQ, the numbers are published on NASDAQ's site. The most recent settlement date was 4/30/2013, and you can see that it lists 27.5 million shares as held short.  NASDAQ gets these numbers from FINRA member firms, which are required to submit them to the exchange twice a month: Each FINRA member firm is required to report its “total” short interest positions in all customer and proprietary accounts in NASDAQ-listed securities twice a month. These reports are used to calculate short interest in NASDAQ stocks. FINRA member firms are required to report their short positions as of settlement on (1) the 15th of each month, or the preceding business day if the 15th is not a business day, and (2) as of settlement on the last business day of the month.* The reports must be filed by the second business day after the reporting settlement date. FINRA compiles the short interest data and provides it for publication on the 8th business day after the reporting settlement date. "First, your question contains a couple of false premises: Options in the U.S. do not trade on the NYSE, which is a stock exchange.  You must have been looking at a listing from an options exchange. There are a handful of options exchanges in the U.S., and while two of these have ""NYSE"" in the name, referring to ""NYSE"" by itself still refers to the stock exchange. Companies typically don't decide themselves whether options will trade for their stock.  The exchange and other market participants (market makers) decide whether to create a market for them. The Toronto Stock Exchange (TSX) is also a stock exchange.  It doesn't list any options.  If you want to see Canadian-listed options on equities, you're looking in the wrong place. Next, yes, RY does have listed options in Canada. Here are some.  Did you know about the Montreal Exchange (MX)?  The MX is part of the TMX Group, which owns both the Toronto Stock Exchange (TSX) and the Montreal Exchange. You'll find lots of Canadian equity and index options trading at the MX.  If you have an options trading account with a decent Canadian broker, you should have access to trade options at the MX. Finally, even considering the existence of the MX, you'll still find that a lot of Canadian companies don't have any options listed.  Simply: smaller and/or less liquid stocks don't have enough demand for options, so the options exchange & market makers don't offer any. It isn't cost-effective for them to create a market where there will be very few participants." "A company whose stock is available for sale to the public is called a publicly-held or publicly-traded company.  A public company's stock is sold on a stock exchange, and anyone with money can buy shares through a stock broker. This contrasts with a privately-held company, in which the shares are not traded on a stock exchange. In order to invest in a private company, you would need to talk directly to the current owners of the company. Finding out if a company is public or private is fairly easy.  One way to check this is to look at the Wikipedia page for the company.  For example, if you take a look at the Apple page, on the right sidebar you'll see ""Type: Public"", followed by the stock exchange ticker symbol ""AAPL"".  Compare this to the page for Mars, Inc.; on that page, you'll see ""Type: Private"", and no stock ticker symbol listed. Another way to tell: If you can find a quote for a share price on a financial site (such as Google Finance or Yahoo Finance), you can buy the stock.  You won't find a stock price for Mars, Inc. anywhere, because the stock is not publicly traded." You have not lost value. It is just that the shares you owned, are now not tradable on US stock exchanges. You still have the value of your shares protected. In cases like de-listing of a stock, typically a trust (may be managed by a bank) is setup to help customers liquidate their stocks. You should try to search the relevant SEC filings for de-listing of this stock to get more details on whom to contact. "Yes, you're still exposed to currency risk when you purchase the stock on company B's exchange. I'm assuming you're buying the shares on B's stock exchange through an ADR, GDR, or similar instrument. The risk occurs as a result of the process through which the ADR is created. In its simplest form, the process works like this: I'll illustrate this with an example. I've separated the conversion rate into the exchange rate and a generic ""ADR conversion rate"" which includes all other factors the bank takes into account when deciding how many ADR shares to sell. The fact that the units line up is a nice check to make sure the calculation is logically correct. My example starts with these assumptions: I made up the generic ADR conversion rate; it will remain constant throughout this example. This is the simplified version of the calculation of the ADR share price from the European share price:  Let's assume that the euro appreciates against the US dollar, and is now worth 1.4 USD (this is a major appreciation, but it makes a good example):  The currency appreciation alone raised the share price of the ADR, even though the price of the share on the European exchange was unchanged. Now let's look at what happens if the euro appreciates further to 1.5 USD/EUR, but the company's share price on the European exchange falls:  Even though the euro appreciated, the decline in the share price on the European exchange offset the currency risk in this case, leaving the ADR's share price on the US exchange unchanged. Finally, what happens if the euro experiences a major depreciation and the company's share price decreases significantly in the European market? This is a realistic situation that has occurred several times during the European sovereign debt crisis.   Assuming this occurred immediately after the first example, European shareholders in the company experienced a (43.50 - 50) / 50 = -13% return, but American holders of the ADR experienced a (15.95 - 21.5093) / 21.5093 = -25.9% return. The currency shock was the primary cause of this magnified loss.  Another point to keep in mind is that the foreign company itself may be exposed to currency risk if it conducts a lot of business in market with different currencies. Ideally the company has hedged against this, but if you invest in a foreign company through an ADR (or a GDR or another similar instrument), you may take on whatever risk the company hasn't hedged in addition to the currency risk that's present in the ADR/GDR conversion process. Here are a few articles that discuss currency risk specifically in the context of ADR's: (1), (2). Nestle, a Swiss company that is traded on US exchanges through an ADR, even addresses this issue in their FAQ for investors. There are other risks associated with instruments like ADR's and cross-listed companies, but normally arbitrageurs will remove these discontinuities quickly. Especially for cross-listed companies, this should keep the prices of highly liquid securities relatively synchronized." "You can group your like-kind (same symbol, ST/LT) stock positions, just be sure that your totals match the total dollar amounts on the 1099.  An inconsistency will possibly result in a letter from IRS to clarify. So, if you sold the 100 shares, and they came from 7 different buys, list it once.  The sell price and date is known, and for the buy price, add all the buys and put ""Various"" for the date. If you have both long term and short term groups as part of those 7 buys, split them into two groups and list them separately." Initially, Each company has 10k shares. Company B has $500k money and possibly other assets. Every company has stated purpose. It can't randomly buy shares in some other firm.   Company A issued 5k new shares, which gives it $500k money. Listed companies can't make private placements without regulatory approvals. They have to put this in open market via Public issue or rights issue. Company B does the same thing, issuing 5k shares for $500k money. Company A bought those 5k shares using the $500k it just got There is no logical reason for shareholder of Company B to raise 5K from Company A for the said consideration. This would have to increase. how does the trading company know which one I want to sell? It doesn't need to know. You just sell one. From taxation point of view depending on the country / tax jurisdiction, it can be only be FIFO or specific stock.